Unlike the 360 you can easily access game saves by simply copying them on a USB flashdrive. Some games are protected from being copied so the only way you can access those game saves is by using homebrew on 3.55 CFW. To copy a game save you need to have an External HDD connected to your PS3 and go to the save file you want and press "Triangle" and then copy. Choose your Ext. HDD and wait for it to copy.
After you will get a folder on your Ext. HDD called something like "BLES####_SV" which contains the save files. What exactly did you want to do with your game saves?