What update do i need?

Hi guys, i have not used my ps3 in like a year now. as at the last check, i was running multiman on it and 3.55cfw. the last new game i had on my external HD was FIFA13. Am pretty sure so many updates would have been carried out and improvements. Can anyone advice on what update i should do and how to pls. I noticed not all games can be played on the 3.55cfw. what generally should i do to keep up to date pls with the latest games and functions.

regards

fluidt7