Ditto on Scott's list of dive operators. You really can't find a "bad" one here or in the Keys.
We don't dive from piers here, since the reef is only about 100 yards off shore at high tide. Lauderdale by the Sea is known as the shore diving capital of the US.
So, as far as where to stay, we have some very good shore diving and a lot of hotels/motels so close you can gear-up in your room and walk out. Do a search on Yahoo from the following map location and pick anything on El Mar or A1A within 3/4 mile:
4200 El Mar Drive
Lauderdale by the Sea, FL 33308
El Mar Drive would be the best place to stay, but A1A might be a little cheaper although it's AROUND the block from El Mar hotels.
I always suggest Holiday Inn, which has the whole block and a dive site right across the street (Palm Avenue). It's also a block south of where I live on Hibiscus.
To find a shore dive, just look here for a thread with the day you're interested in. If there isn't one, just follow the example of others and post your own (ALWAYS include the date & place in the header, ie "4/1/04 Lauderdale by the Sea AM dive."
They Keys are worth a trip from there, even if you've been before. I leave 3 hours to drive down to Key Largo and am always early enough to have leasurely breakfast before embarking. Of course, you have to time the traffic. It's a full day, so you'll be back the same evening no problem.
Another option is Venice on the West Coast, where we dive for fossilized shark's teeth. You'll get 50 your first outing if the visibilty is good.
The weather usually cooperates, so you're bound to have a great trip. Be sure to organize a shore dive while here to meet the gang.