VS 2010 Controls out of line on different PC's

Hi,

I have a webpage with labels on the left and textboxes to the right. In my css I have set each textboxes margin-left so they all line up. Do I need to set the font / size in the body of the webpage? Also how do I find out what font / size Im using on my development PC? I have spent hours getting all my webpages lined up.

Many Thanks

Jiggy