Bend is a good paddling town but it is different than the rest of Oregon because it is on the east side. There is not much but the Deschutes. The Deschutes is a really strange river. It does run all summer from dam release which is good. It is pretty much flat except for where the river pours through recent lava flows forming (sometimes gnarly rapids). Your options near bend are: first street- really crappy playspot, big eddy- one long 3+ rapid, meadow camp- great 4+ run (some of it over 200 fpm), lava island falls- 5, dillon falls-5, and benham falls- 5++. There is also more class IV downstream from town that runs in the fall after the irrigigation season is over. Basically, its a good river if you are a IV+ or better boater.
In addition, there is some illegal irrigation canal boating to be had. The best spot is Area 51 which is about thirty minutes from town in the middle of the desert. Get directions from a local.
Then of course its 2-3 hours to all the stuff on the west side of the mountains. See the Oregon Kayaking website for that info.
Hope this helps- Josh.