If the reason they were asking for a resume was simply to figure out which group in which to put you at camp, then Mick's advice is sufficient.
However, if there are recruiters at camp and they are looking for officials, then I would include any officials associations to which you have belonged. If you are a NASO member, list that, because it means you have insurance coverage.
If you have any letters of recommendation from previous camps or off-season leagues, include those, too.
It is always best to keep your resume (not including testimonials) to a single page.
And...use your spell checker.
