1) Skip To My Lou has links to ten apron tutorials and patterns which include the likes of T-Shirt Aprons, The Ruffle Apron, and Cottage Chic Cooking Apron.
2) TipNut has an outrageous (56!) number of links to free patterns, including knit & crochet, vintage, and aprons for men and children. Just a few of the patterns included in the site are 50's half aprons with tie-pocket, Martha Stewart's Bakers Apron, and 3 Darling Aprons for Girls.
Tip Junkie has 24 free apron patterns with pictured instructions. To name just a few patterns, beautiful Krista Apron, Retro Ric-Rac Apron, and a No Sew Pattern (from tea towel) for kids.