Whether you are willing to spend $200 or $500 USD, finding an inexpensive guitar is not hard to do. There are plenty of good Web sites I will mention later on but what's important now is getting the answers to the 2nd part of your Q.
Plan on spending 2-3 hours at a large, friendly music store near you. You'll need a place where they will not hound you to make a purchase. In this setting you will learn about guitars. In the States, Guitar Center is one such place.
If you aren't near a store like one described above, find the nearest one and go. Either go w an educated friend or do some research if you have to go solo. I'll help w the research part shortly...
Once you visit a store, ideally you will walk out much more informed. If you have'nt already made a purchase you will be able to go to a good Web site for affordable guitars such as Musician's Friend.com, Sam Ash.com, eBay, maybe even Amazon.com.
Now for the meat and potatoes: What should you be looking for in said affordable instrument?
-Strings should be low but not buzzing.
-A straight neck. Any good gtr store will do a free guitar neck 'set up' for you after you make a purchase.
-Good 'pick-ups'. These are the things under the strings on the guitar's body. Without them there would be no amplified sound.
-The same two top concerns (above) are apply to acoustic guitars.
Don't worry about pick-ups unless the acoustic you are getting is an electric acoustic guitar (an acoustic guitar that can be amplified).
-Storage (especially for nylon-string "Classical" or Flamenco guitars). Acoustic guitars are not solid-bodies like most electrics so where they are stored requires more consideration. Case in point: guitar case humidifiers are available for more cautious acoustic guitar players/performers.
-There are more considerations, but Warranty / service is important, of course, for both (elec. + acoust.).