You made it to part two, new meditator!
The second question new meditators usually ask me is 'What should I think about while I sit there?'
The most important thing to remember, especially for you ultra-disciplined athlete types, is to give yourself compassion. When your mind wanders to worries or begins a mundane to do list don't flog it back into line, gently refocus your attention on your intended object. The point of meditation is awareness not to achieve some sort of spiritual goal on the cushion.
Here is a quick list to get you started.