A pan is essential. Ya gotta have that. However, a small sluice-box will make things go much easier. If you're in an area where you can legally pan/sluice in the stream, set the sluice up, and start feeding dirt slowly into the sluice. This is a good family activity; you can have one more of the kids digging material into a bucket, then haul that over to someone that is feeding the sluice. When you call it a day, do a clean-up.

Check you heavies! You'll get more than gold. Garnets tend to show up a lot as well. If you're truly worried about putting dirt into the stream, you might try to take the dirt home and wash it there. You can use some large tubs to hold water. Also, it might be a good idea to NEVER DUMP YOUR CONCENTRATES. The gent that does "Gold Fever" always saves his concentrates, and takes them home. He has a custom-made wash plant in his basement/garage, that's designed for catching the truly fine, "flour gold" and/or gold dust. Instead of a sluice, he uses the corrugated green plastic drain tubing for riffles.

You might want to have some cheap magnets around as well, to help pull the black sand out (it's raw iron ore).