How to get used to running?

I have been dancing for a few years, and recently I have decided that I want to play field hockey in the fall. I want to start running over the summer so I won't be so far behind during the season. The only problem is, I'm not that "cardiovascular-ey" fit. I dance though, so I would consider myself in shape. I have problems pacing myself when I run, and I also have bunions and knee problems which.. I'm hoping the problems can be avoided if I act sensibly! Any tips or "schedules" for starting to run?