Used Cars: Help buying first car, independent mechanic, decent figure

Question
I am in my late 20's. I have only had one car and it was in a fire. I need to look around for another. I have time to look around, I am borrowing my brothers for now. I don't think I can go over 3,000, unless I finance. And I'm not really sure if that would work b/c I do temp jobs. How do I even go about looking for a used car? What are some things to look for? Is the milage important? Can I have a mechanic look it over before buying? Could my budget price be higher? Any advice will be appropriated! Thanks!

Answer
First and foremost look for new and used dealerships that have been around for a while, have good reputations, and will offer you to have an independent mechanic check it over before you purchase it.  When you are talking about purchasing something in the $3000 range, you cant really expect to much, but still you should be able to get something decent.  Figure out what you need ie: car, truck or suv, 4 door or 2 door, automatic or manual transmission.  See what is available at local dealerships with good reputations and time in the business.
Just ask these places how much they will negotiate on a cash deal, and try like hell to not finance a car.
If you have a mechanice friend, who will more than likely be working on this vehicle for you, ask him what he favors.  Because I can sit here and tell you imports are much better cars, but they are also a little more to get fixed, especially ones at this price range.
And realistically speaking, cars at this price range are a lot more about their condition, and how well they were taken care of, then what they are.  And that needs to be a decision your mechanic helps you make as for the true condition of the vehicle.