Some people will tell you that pull-ups (overhand) are the way to go and some people will tell you chin-ups (underhand) are the way to go. Both schools of thought are correct, but the thing they're not taking into consideration is that each exercise is working two different sets of muscles. You should totally do both.
Pull-ups are a really tough exercise to do regardless of your level of strength. To do a pull-up just grab an overhead bar roughly a little wider than your shoulder width apart and pull yourself up. This will really engage your lats.
Chin-ups are also a tough exercise but now you have the support of your biceps to help pull you up. Just flip your hands to the underhand position on the bar and pull yourself up. This variation of the pull-up is a little bit easier to do.
There's definitely more technique involved but these are the basics.
Contact us for a free class and we'll get you pulling up both ways with ease!