How do you want to purchase, and how much are you willing to spend?
Used car lot, private party, Ebay, Craig's list, private auction, goverment repo........The list goes on and on.
If auctions are the way you would like to go, then get yourself a Kelly's Blue Book. Decide on the model and year, look it up, and don't get carried away with the auction atmosphere. Have you ever spent yourself, or saw auctions on Ebay, where you have a $20 Home Depot gift certificate, and the bids are exceeding $40? The same could happen at a car auction. You can easily get that "I got to have it" attitude, and the entire purpose of going to the auction is gone.
If a private party purchase is want you are looking for, then check it all out good. If you have a mechanic, it is a good idea to have him check it out for you also.. Ask lots of questions, and get the details of the vehicle's past history. The same goes for a dealership purchase.
Purchasing your vehicle shouldn't be difficult. There are many public auctions with great selections and amazing prices online. A quick visit to http://matdeb.bezoogle.com/pp/auto-bargains will give you an idea of some ways to shop for your new vehicle.