There are several sites along the river. The good ones are designated and have BLM markers (post) with the site name on them. If you are running from Pumphouse (good developed BLM campsite at the put-in) to Rancho or State Bridge, you can break the run roughly in half by camping at the sites just below the first gorge (Eye of the Needle rapid) and the hot springs (river left). There's a site about a 100 yds downstream of the hot springs on river left and it's ok. However, there's a better site around the bend called "cottonwood". It's great and has picnic tables (and maybe a pit toilet). Once below these two sites, there may be a few more before Radium but I'm not sure. You can camp at a BLM site at Radium (car supported) or continue downstream through Yarmony rapid and head to "island" campsite. It's sweet. Below that there are several other sites, mostly on river left. One good one is "bench" campsite. Regardless, get an early start if you're going to camp on the river. Since there's little water left anywhere, the Pumphouse has been really busy.
Tracks are right there and there's a lot of train traffic, which is cool during the day (especially the Amtrack trains) but can get old at night. Bring ear plugs if you're a light sleeper.
The fishing has been pretty good but there's a lot of fishing pressure right now.
If you take out at Rancho, be ready to pay a fee. I think it's $3 per car and $1 or $2 per person after that. They have a nice ramp at the take out. They'll run your shuttle as well which runs about $30. The only downside is that they drive your car, they don't drive you in theirs. You can also take out at State Bridge for a fee. It's $3 per person and they have a decent ramp as well.
At the Pumphouse put-in, I'd use ramp #3. It's generally less crowded and the ramp itself makes putting in very easy.