Hi, I am 5'1" and I am looking at getting my first bicycle. I am only looking to drive for a little exercise and for some fun. Any ideas on what bike should I get and the specifications (height of bike etc) ?
The bike you want will depend on where you want to ride. Walmart and other department stores will have a one fits all bike and it will be low quality. You want to visit the local bike shop and tell them what you want to do and expect from a bike. They can help you select the correct bike and the correct size. If you don't want to spend that amount of money it will give you an idea of what to look for used.
If you are looking for a great head lite Ed has the link.
Probably going to need a Small or an XS frame but no tellin' until you go to a shop and stand over and test ride one. We could go back and forth here for a long time on that. See here for ideas: http://www.performancebike.com/bikes/Product_10052_10551_1030710_-1_31500_20000_31507 Seven pages of bikes to look at and if none of these do it for you then look at all the others. Thumbs up to Bob too!