The Redwall Character Guide
Two good things to know when you start a character are the gender and species, which are relatively easy things to figure out.
For your first character, a good choice is to make that character your own gender. First, it's the most memorable of your characters, and having people remember you as a girl, when you're a guy, or vice versa, can be very confusing. Also, it's the easiest and most natural to do.
When thinking about the species of your character, you have a few things to keep in mind. First, the basic personality (we'll go in depth about it later). Are they bad, and mean? Then they should probably be vermin (although it's prominent in the ROC, and talked about a little in the books, good vermin get annoying because they spend half their time telling people that they're not bad, but actually good. If you have no desire to explain your life story over and over and over again, it may not be the best idea for you). Are they going to be good beasts? Then they should probably be woodlanders (even if there are evil woodlanders in the ROC, there are few if any in the books [it's a debatable topic]. If you want to have more interesting role-playing, it'll be good to stick to the generic).
Character species are pretty versatile, and so you have a pretty good range to choose from. There are, however, a few species to beware of. First and foremost of which is the badger. Strong and powerful, they are rare in the books. However, not so in the ROC, where badgers are plentiful. The main problem with badgers is that they are often mooched, with their players making them all-powerful. Without a firm and inventive personality and history, it is very easy to make a mooched character.
Another thing to remember is the general traits of the character. For instance, Foxes are sly and cunning, hares are loud and quick. Moles are sensible and simple, and dormice are often sleepy.