Well there are two types of food photography: product shots (for menus), and food documentation for blogs, recipes etc.
Product shots are a whole different ball game. Often these "models" are constructed using materials that simulate the look and texture of the food--designed to stand up to rigors of product shots. For example, using lard to for shots Ice Cream--since Ice Cream melts quickly, it's hard to take multiple shots under hot lights. So the next time you're at a Burger King and you wonder why your Whopper looks nothing like what you see on the menu, it's because they used something like beets instead of tomatoes.
The other type, is more of a documentation style, in which you try to present dishes served in an appealing way. To me, this is more fun (since I'm a total foodie), so these tips are geared towards photographers who wish to document meals and dishes, as opposed to making images that look like food.
Here is the first attempt I made at food photography. Shot with a 5D2/Canon 50mm f1.4.
And here is the second attempt. Shot with a 5D2/Canon 50mm 2.0 Macro.
Some tips that have worked for me:
Natural light is so much better than flash. If you are shooting your own creations, place them on the table near a window during the day and get up on that lovely light!
Shoot the dishes right as they're plated. Since this isn't food science type, you don't have much time. Shoot the food quickly.
Shoot from a just-above table perspective. Photographs that look like images we see every day aren't as visually pleasing, so a top-down shot of a bowl of soup looks worlds apart from a shot from just above the table.
Gorilla Pod or Handholding. Since the 5D2 has awesome high-iso performance, I can shoot in dim lighting. If your camera doesn't have stellar high-iso, then invest in a gorilla pod, or other similar pocket tripod. Handholding is much easier to frame the shot in, so thats what I stick with.
Set the image properly. Move other dishes, glasses, and silverware in and out of the frame as desired. During the 35 courses at elBulli, I was constantly shifting things around to get an image I thought would be compelling.
Look for interesting angles. This may be personal preference, but food lends itself well to angles. For each dish you shoot, try a shot from a different angle.
From the techincal side of things:
I try to shoot with the largest aperture available to give a nice DOF, and to produce a nice bokeh (background blurring).
I use 50mm for a nice tight-crop of the dish.
Macro lenses will let you get a nice in-close focus of your subject.
Specific to photographing your own food:
Use a cloth to clean up any aberrant sauces, food particles etc. You can clean these up in post-process, but much faster if you don't have to.
Garnish is key. The sprinkle of green onions offer a nice contrast to a bowl of New England clam chowdah.
Think about your dishes. White dishes are fairly pleasing as they brighten up the dish, and give good contrast to the food contents.
Think about your table setting. White table cloths, like white dishes, will brighten up your image.
If you're at home, you can use your own tripod, and forgo buying a table top one.
Most importantly: Have fun. Food is a social experience that is so much more than just a combination of nutrients. Keep that in mind, enjoy your food, and have a good time taking pictures of what you're eating.