1. Start with what you like
Rather than divulging yourself into a comic book universe (or maybe many), focus on one character or a team (X-Men, JLA) only. Even independent developers have large universes. Pick one of the most popular characters or teams from one publisher that relate to you the most and stick with them. This way, you can track that certain character or team without losing yourself within the comic's universe. Also, take genres into consideration. Looking for a bit of sci-fi? Check out Dark Horse and have a look at their take on Star Wars. For example, if you choose Wonder Woman as your prime candidate and during that time, the more recent issues of Wonder Woman would be a good place to start. Once you are familiar with such a character, you may lose interest in them. Remember, this is only so you can get yourself started in comics, but they may also become your favourite character. Once you being with that certain character(s), there may be cross-overs. Using Wonder Woman as an example again, you might want to start with the runs by writers such as Greg Rucka and Gail Simone. If you want something a little further back, try the Wonder Woman Chronicles trades, or her Showcase Presents volumes.
One daunting issue concerning new collectors is the high issue numbers of long-time ongoing series'. When you want to read a book about a particular character you may feel like you are coming in too late when current issues are being published with issue numbers in the 400's, 500's, or more. Do not be afraid of high issue numbers. Comic writers will periodically give users "jumping-off" points at certain issue numbers (often at the 50's or 100's) to start a series. Larger series' are also divided into different "story-archs" which serve as logical partitions of the larger series, typically lasting between 2 and 6 issues. These smaller subplots interconnect to form the larger idea. Regardless of where you start out in a book, these divisions can give you the feel for a new book. If you are concerned about catching up on the back-story you have missed (after all, some of these series' have been going on for decades) you can look for used books to fill in the gaps later, and read encyclopedia articles from ComicVine to give you an idea of what you have missed in a character or team's history.
Another way to catch up without picking up individual issues is to collect Trade Paper Backs (sometimes referred to simply as "trades" or TPBs). Trade Paper Backs are reprinted collections of issues (generally by story-arch or series, but sometimes by general theme), and can be purchased new or used at a variety of stores. If you are more interested in reading books, and less interested in the physical (paper) copies digital comics are rapidly becoming an interesting alternative. Some major companies such as Marvel are now putting digital copies of their books online. Some of these books can be viewed for free, and others can be purchased or subscribed to digitally.
2. Comic book stores
What you need from a good comic book store is a good selection of your chosen character and staff that know what they're talking about. With most comic book stores, a pull list is available, which allows you to select your favourite comics each week and the staff will collect the issues when they come in, and comics arrive on Wednesday. Many will also give you a discount to have your pull list or "folder" with them. A comic book store is also preferred if it is clean. Such things like dust will deteriorate the comic book's preservation. Lighting is also a bonus but probably not always needed. However, lighting allows you to see the comics properly and to see what state they are in. This does not hold for sunlight, which can damage comic books. Also, try not to spend too much too quickly. Modern comic books are often released in limited quantities with special variant covers, and because of their associated rarity these books may sell for many times what normal books cost. Antique comics of your favorite characters are also often available at comic book stores. While these types of books may be tempting, remember to go slow. New collectors may wind up with a collection of books that they overpaid or are otherwise unhappy with because they spent too much too fast.
If comic stores aren't in your present area, using a mail catalogue order is useful, as you order the comics you would like on the Internet and they get sent to your door. Payment is usually through credit card. Buying from a company's site also allows you to receive discounts from the original price if you subscribe to their services. Other sites like eBay and Amazon also provide comics to buy at discounted prices and mostly good condition. Also, comics are not restricted to comic book stores, even though they are the preferred place to buy. Major book stores like Barnes and Nobles also sell comic books.
Another place where you can get the opportunity to read more books without having to spend money is your local library. Many libraries are starting to obtain Trade Paper Backs for you to check out and enjoy without ever spending a dime.
3. Comic Book Care
Caring for you comic books is important if you ever want to pass them down to the next generation or want to re-read them. The easiest way is to buy bags and boards for you comic books from the comic book store, and place them in short or long boxes, which are also available at comic book stores. This will seem like a money waster, but it will pay out in the end and allow your comics to look much nicer. Check out Comic Book Care for more information on other options on how to take care of your comics.
4. Comic book databases
Take note of each comic book that you buy. You could use a notebook or a spreadsheet application on your computer. Keep track of your collection while it's still young, so if you ever miss an issue of a certain comic book, you can go back and attempt to find it on eBay or something. Also, you can check out the back issue section in your store and see if they have anything there.
5. Be cheap for once
As with any hobby, collecting comic books can be expensive. Sometimes, your local comic book store might have a sale on for some really old comics. Get it while you can, because this can be great to growing your collection. However, don't buy everything that's on sale. Just focus on your focused character. This will allow you to add more depth to learning about the history of your chosen character. This also allows you for something extra to read when you've read everything on your pull list.
Also be on the lookout for cheap comics elsewhere. Some places where great deals on comics in a variety of ages and conditions are yard sales, swap meets, and flea markets/malls. Be careful not to spend too much at these places because they are also great places to get ripped off. If you are still new to comics and do not understand the subtleties of comic book grading, or do not have an idea of what comics from different ages are worth you may get suckered into a "great deal" that turns out to be not so great. Such salesman may not be bad people. They may have little more idea than you of what their books are worth. If you are collecting for your own personal enjoyment you can hardly go wrong spending a dollar or less on comics. Sometimes you can find them as cheap as a quarter a piece. As mentioned earlier second hand auction sites on the internet can be used to help build a collection for chap, however be careful. There are many dangers (primarily being ripped off) associated with internet auctions, so use these sites at your own risk.
6. Attend a comic book convention
Attend a comic convention, such as ComicCon. Doing so will allow you to interact with other comic book lovers and maybe allow you to make a friend or two sharing the same favourite of a character as you. You also will often have the opportunity to meet the writers and artists behind your favorite books in person, often getting a signature or sketch while you are there. Attending ComicCons also allow you to buy plenty of issues missed on your chosen character and browsing through all the booths are enjoyable. Also, you may also get some news on new and up coming comic storylines and new movies that are being made. ComicCons may not always visit your city, but that doesn't mean it will stop you from attending smaller ones.
7. One more thing - enjoy it!
Don't take this hobby too seriously, unless that's what you want. Comic books should be enjoyed by everyone and each character should be respected. Voicing your opinion may induce some interesting discussions, but in reality, they are created to be read. For example, some comic readers use it as a means of escape. Also, don't be embarrassed if you don't know much about your favourite character. Comic books are meant to be a world of discovery. Starting from where you are and enjoying yourself with his hobby is all you need. If someone knows about Spider-Man's webbing chemicals more than you, then let them. Bottom line is, enjoy the comics as they are and if you wish to continue into something even further (like knowing everything about Spider-Man's webbing chemicals) then you are welcome to do that too.