Lunch in a Box has great ideas for cooking for little kids and has amazing ideas about how to streamline your bento making mornings.
and Just Bento has very healthy and simple bentos. Plus great photos.
If you are a highly skilled bento artisan google kyaraben or oekakiben for divine inspiration.
Also if these sites are not your cup of tea then check out Cooking Cute or check out the books at your local book store. Bentos are increasing in popularity and it shouldn't be too hard to find some great ideas for your bento needs. ENJOY!