A T-shirt quilt is very tough for a new quilter. Find someone who knows about quilting and ask them to assist you or at least to be available for questions. One bit of advice I give to folks doing a T-shirt quilt is to look at it in stages rather than the whole quilt. First, lay out the shirts and get an idea of what you want to do (this may change over time). Then, rest, then stabilize the shirts and cut out the pieces (include generous seam allowances at this point). Then, at a later date, start looking at how they will be laid out. Doing it in stages may help you from feeling overwhelmed and let you build your confidence. Good luck!