Welcome to the forum. The caresheet that Stefan posted should give you the essentials, anything that isn't in there you can probably find by searching the forum, or just ask and we'll do what we can to answer your questions.

To tell whether it's male or female you need to look at the shape of the tail. There's a thread here: http://www.thamnophis.com/forum/bree...xing-pics.html that shows the difference between male and female garters, if you aren't sure about yours then post up a photo like the ones in that thread and some there's plenty of people who can offer their informed guess.