What cost-effective things can I do to help my knives stay sharp longer?
Here are a few rules I follow with my own knives.


Don't put your knives in the dishwasher. Hand wash and dry immediately after use.
Store knives where they won't be banging up against other hard things: my favorite is in a wooden knife block.
If you must store your knives in a drawer, protect the edge. You can use a commercial solution like this guy, or cardboard and tape if you're on a shoestring budget.
Don't cut on a glass cutting board. They look nice, but will dull your edge.
Get a steel and use it. A steel is not for sharpening, but for maintaining a sharp edge. Honing with a steel before each use will help keep the edge straight and sharp.
Don't use dull knives. Either learn to sharpen yourself, or have them professionally sharpened.


Slightly off topic, but if you're a starving college student who wants to have a high-quality knife or two at a very reasonable price, take a look at Forschner/Victorinox.  Yes, the Swiss Army Knife people. I was turned on to them by professional chefs, and have found them every bit as high-quality as my much-more-expensive Henckels and Wustof-Trident knives.