I'd like to add what I tell every inquirer, etc., who asks:
Practically, it helps to look at the meals you already like to eat and see which ones are already fast appropriate or might be made so with a bit of tweaking (not adding cheese, for example).
The following comments cover foods that contain no meat or dairy.
It also helps to investigate the various ethnic foods. Mexican (rice and beans), Italian (pasta with a simple sauce and/or veggies), Middle Eastern (hummus with pita, lentils & rice with carmelized onions - I'm cooking this right now!, various rice, bulgar, chickpea, veggie dishes), Asian (veggie/tofu stir fries with rice). I know many people who love Indian food during fasts, but I personally have issues with some of the spices.
If you're in a cold climate, this is the perfect time to try out veggie soups and stews. Making them in the crockpot is very easy if you have one.
I often like to make a big pot of something and eat off it until it's gone (I'm single so I don't have to worry about someone else getting bored with the food!).
You can even mix things up - cook lentils, season with Mexican spices, and eat in a tortilla with salsa.
Breakfast is easy - oatmeal (with or without soy milk), cereal with soy/other non-dairy milk, bagel with peanut butter or jam.
Lunch is either leftovers from the night before or things like a peanut butter & jam sandwich or even PB with sliced bananas (rather filling, too).
If you're on the go a lot and have to get meals out, don't despair!
Many places, even fast food such as Subway, have things you can eat. I like veggie subs, just tell the place to leave off the cheese and mayo.
Note on label reading:
As I've been told by several priests, if the package indicates in large letter on the front that meat or dairy is in the food item, don't buy it. For example: margarine that indicates it contains "sweet cream" or "beef soup." However, don't go reading the fine print ingredients list.
Depending on which jurisdiction you're in, the fasting might be a bit different. Some will allow fish on all fasting days outside of Great Lent/Dormition Fast. Ask your parish priest.
Start off easy - it's easy enough to give up meat on Wednesdays and Fridays, eat simply, and smaller portions. Try to do without snacks between meals, if you don't have a health condition that requires you to eat frequently.