Well, if you have a marker that is capable of firing on Co2 (some aren't, mostly the high end ones), they should pretty much accept all bottles. If you have an old school marker like the VM68, it'll only take 7oz bottles, because they go underneath the barrel. So anything larger won't fit.
Basically all Co2 bottles use the same valve, meaning they can be screwed into all standard air source adaptors (asa). The larger the bottle, the more Co2 it can hold, the more shots you can get from your tank before needing a refill.
As far as the refilling goes, I recommend getting that done by someone who knoes his stuff. It's high pressure stuff you're dealing with, so you don't want to mess up. When you do get your own filling station, make sure that the place you get it from gives you a full and detailed explanation on how to use it.
Good luck!