You can get all the recipes and tips you could ever need over on YumSugar, but if you're partial to Martha Stewart (and who isn't?) then you should consider downloading the Martha's Everyday Food app ($1) and keep all her great recipes in your pocket.
The iPhone is already a handy cooking tool, so pairing it with Martha's app makes it a match made in cooking heaven. It's easy to tote your smartphone in the kitchen, and utilize the app, which contains all of the recipes you find in the Everyday Food magazine. Plus, the app is updated monthly with new concoctions found in the physical mag, so you never get bored and the app won't go stale! Get it? Stale? Yeah, I thought that was pretty funny.