i want to read the green lantern stories that revolve around all the other lantern corps as well like sinestro corps and blackest night and all these stories aswell as all the other important stories by geoff john like gl rebirth but am unsure how to go about ...

Go on ebay and look for "Green Lantern TPB lot" for a week or so. You can probably get them for half price. It's all a good read.

Like Rich said, get the trade paperbacks from ebay. If all else fails check amazon or local shops.

These arent by Geoff Johns but check out the current Red Lantern and Green Lantern Corps comics.

@adamjh95: You mean reading order, or how to get the books?

If it's how to get the books, the advice already in this thread are the best pieces of advice you can get.

As for reading order, just follow, more or less, this order:

Secret Origin

Rebirth

Sinestro Corps War (first time we get another corps, other than green).

Rage of the Red Lanterns

Agent Orange

Blackest Night

Brightest Day

War of the Green Lanterns

...and that'll take you into the n52 territory.

thanks for the advice