What is a good way to keep my tires from going flat easily? Title says it all, how do I keep my bicycle tires from going flat easily? I live in an area with a lot of sharp stuff (think glass shards, nails, cactus, etc)...
There are a number of things you can do:


Puncture resistant tires.  These have kevlar/aramid belting in the tire, thicker rubber or other features that make them harder to puncture. Would need to know more specifics about your bike (especially wheel/rim size) to be able to suggest specific tires, but Specialized, Continental, Schwalbe, and pretty much every other major tire manufacturer have a wide range of puncture-resistant tires. You can probably just go to your local bike shop and ask about puncture resistant tires, or you can order them online a number of places. There's a bunch of good suggestions here for specific types: What type of tires can prevent goatheads?
Puncture resistant tubes.  These seem to be harder to find.
Slime/goo in the tube.  Personally I don't care for this, but some people swear by it.  This is a sort of thick goop that goes inside the tube; small punctures will get filled in by the goop.
Tire inserts.  These are kind of like a belt that goes between the tire and the innertube, stopping sharp pointy things from going into the tube.
Keep tires well-inflated (near the top of the recommended pressure).  This reduces the size of the contact patch and makes it more likely stuff will glance off the tire. You didn't mention them in the question, but this also prevents pinch-flats.
Avoid riding over sharp pointy things, especially when there's water around.  It's much easier to cut or puncture rubber when wet, since dry rubber tends to grab glass and metal.


Also, if you do get a flat, make sure to check both for remaining pointy bits and gashes in the tire large enough for the tube to herniate out through.