okay
try to take a screen shot of you hp before you power up, and then after you power. Include a bit of text that you power up whatever amount from the start to finish etc.
You can make reference to traci's article and the one from hivebuzz, mention this is your first pud, and perhaps your goals for hive and how you are finding things.
Make sure you use the correct tags, as that is how you post will be found and name put into the competition.
You can write whatever you like really, just mention it is a PUD post and the amount you are powering up etc.
As long as you have the tags and the amount you power up and make it plain it is a power up day post then that is the minimum you need, so just add a bit more. If you search the tags you can find some examples, but don't worry about it too much. You can say you joined hive on such and such date, you have seen you account grow by x amount per week or month. Do you use any of the stats sites?