If you are talking about a typewriter effect (cf. my comment), you can find jQuery plugins like this one.
If you mean actually drawing the letters, then it's beyond jQuery basic capabilities and you would need to look at graphing/charting libraries instead.
[edit] Note that it is easy to create a simple typewriter effect in jQuery (or JavaScript) without a plugin, see a couple examples here (including my live demo). However a plugin will help if you need to deal with html, not just text.