Begin by looking through these guitars. A good beginner guitar should be an acoustic guitar. I recommend buying a relatively cheap guitar because you can always upgrade at a later date. Another reason is because some more advanced guitars can be extremely pricey, especially when you include the price of amps and accessories. With a cheap guitar, you have the ability to do what you wish without the guilt of harming a more delicate item. Now, this is not to say that you should destroy it in the process of learning, but it gives more leeway.
Tabs are very easy to learn and understand. When you look at a guitar tab, you will see six dashed lines, each representing a string on the guitar. The top line, however, represents the bottom string on the guitar (the high e string when in standard tuning). The numbers on each of the lines simply represent the individual frets on the guitar. You just place your finger on that particular fret of the string to play the correct note. For example, if you see a "5" on the second line from the top, you place your finger on the fifth fret of the second string from the bottom (the B string when in standard tuning).
Generally, you can use any type of guitar for any style of music. In my experience, however, I have found that certain brands suit specific styles very well. For instance, Fender Stratocasters suit classic rock types very well. If Fenders are too advanced or expensive, try the cheaper brand known as Squier. For heavier music, some good brands include Gibson, Shecter, and Music Man. If these are too advanced or expensive, look into Epiphones.
To view various accessories for your guitar, try looking here.
Good songs to begin with: