Hi - I have found that there are loads of free crochet (and knitting) patterns on www.ravelry.com - nearly all of them have photographs and there are comments from members who have actually made the garment, so you can see it on a proper person instead of a carefully posed model! I find that this gives you a more realistic expectation of what your completed garment will look like on you!
Amazon.com also have a book called from needles to hook which they say is a complete guide to converting patterns from knitting to crochet, although I have never tried to do this as I have always found a crochet pattern that fit the bill.
Hope this helps, Di