T-shirt printing is very easy but can become very complex. However no worries! It's actually really easy to design a shirt and get it printed correctly. You can definitely draw your designs or create them on the computer...or even both...For you, as a beginner and all beginners...one color designs are the way to go and then you can work your way up to more ink colors and more complex designs. First off you'll need a scanner if you're going to create a design by drawing. I would draw the design in pencil, and then outline it in marker. Scan the design as a black and white image at a pretty high resolution. Now here is where people split off...there are those who deal with vector graphics (possibly easily known to you as clipart) and there are raster graphics (dealing solely with pixels like pictures from a camera). For this scenario we'll say you're into raster graphics so we'll use photoshop. The main thing here is to make sure your resolution is high (300 dpi is most standard in any type of printing.) As long as your design is to size and and is at a high resolution...most likely we're almost done. When you give a design to a printer, and for this one color design all you need to tell them specifically is "hey print this in red ink" or whatever ink you want it in. I won't get into cost but it costs more to print on dark colored shirts because there is more labor involved, but that's about it. There is much more to it but hey...it's the simplest I can do on this forum.
http://img12.imageshack.us/img12/7457/bikeskg.jpg
applying graphics to t-shirts 
