I ended up on a 10 day round of prednisone after a bad allergic reaction to poison ivy a few years ago. Like Amy said, the first couple days I was unusually hyper, but that was about it.
If you Google prednisone symptoms you will typically find LONG TERM side effects. 10 days on the drug won't do anything. People that have to be on it for months or years for whatever reason tend to have issues, but if it's just a matter of getting your sinuses back down you'll be fine.
Just make sure you take it as the directions say. Most pred doses taper off, so you take 4 one day, 3 the next, then 2, etc...I think that's why people get jittery the first few days, because you give your body a big dose to let it do its thing, then start tapering down.