Superman/Action Comics New 52 Era

Hi i am looking for help on this matter. I have started to collected the collection editions of superman volume 3. And i came across something. "action comics" Which seems to have superman in it?. I am relatively new to collecting these comics. Is their anyone who can help?. What does action comics cover is it set before superman volume 3 or after?. I notice Kal-el in jeans in one pic i think it is. Also i live in the uk and getting the weekly or is it monthly issues so i decided to collect the collection editions as i can get them easily on amazon. Am i missing out on anything not getting these monthly/weekly issues?. I am not even sure how often they come out?. I am a major superman fan but all of my fandom comes from tv/movies. Any help with these new 52 comics would be great. Just one other thought, Convergence whats that? lol is that apart of the new 52 universe?.