Just remember one thing- The first bike you get will only serve one purpose. That is to tell you what sort of bike to get next.

I know when I started- Finance was tight and bought cheap. Too cheap possibly but I did not know if I was going to enjoy riding. Gradually over the years- I improved the bike for the type of riding I do So I lied- The 1st bike will only serve to get you started on the type of bike you should have bought in the first place.

Last year I had a Mental aberation and got a road bike for the first time in my life. A cheap Giant OCR3 and all that told me was That I should have got a better bike.

Only a couple of things to think of- Find a local Bike shop (LBS) that will treat you right- You may change these a few times over the years aswell. And get a bike that fits. That is wherre the good LBS comes in as they will get that right for you.