Berkeley is full of enthusiastic sailors who would love to have an opportunity to sail in the Friday Night Races. Some of them might be experienced racers, but most are beginners. So there are two strategies, depending on whether you absolutely need experienced racers to crew on your boat, or whether you can handle beginners.
1) To find experienced racers: The best resource is the Cal Sailing Club. The "regulars" at CSC know all about the Friday Night Races and Chowders, but there are always lots of new members coming in, and many of them qualify as real "ringers". You can find them there on Sunday at 1:00 PM right after Sunday morning racing at CSC. Or any afternoon or evening, simply walk into the clubhouse and ask "who wants to race on a big boat this Friday?"
The obvious recruiting techniques are also worth trying: cards on bulletin boards, Latitude 38 crew list, postings to newsgroups such as rec.boats.racing or the sailing conference on The WELL. But face-to-face contact is always best.
If you get some volunteers, the next step is to figure out how much experience they really have. The sequence of questions might go something like this:
"How much sailing have you done?"
"Have you done any racing?"
"Have you ever trimmed a spinnaker during a race?"
"Have you ever won a race?"
"What's the most important race you've placed well in?
That should give you a very quick idea of the kind of experience this person has to offer. Be aware, however, that if you need crew that have more racing experience than you do, it's not realistic to expect them to become regulars. They'll meet all the other owners, and if your boat is a little on the "cruisy" side for their tastes, or if they feel they're not learning anything from you as a skipper, they will switch to a more competitive program in only a couple of weeks. But trickle-down works in Friday Night Racing, so if you recruit some hotshot that jumps ship after two weeks to sail on a winning boat, that necessarily frees up some mid-level crew who might end up with you.
2) If you don't insist on experienced racers, you have a huge pool of prospective crew to draw from. The Cal Sailing Club is full of them, so is Olympic Circle Sailing Club and Cal Adventures (next to CSC on the south side of University Ave). Expect to be running a combination sailing school and race boat, but also expect a little bit of crew loyalty. If the personalities are a good fit this should come naturally.
The qualities you're looking for in new crew are enthusiasm and learning ability, even if they're rank beginners. Learning ability is something you'll have to assess subjectively, but there are some tricks to figuring out who has the enthusiasm. Most of these involve assigning "homework" that will further the race effort. Good beginning crew should: a) buy their own digital count-down watch; b) always have a copy of the race instructions; c) learn how to read a tide book and know the tides in advance for each day of racing; d) memorize the applicable code flags. Add a new one from the list every couple of weeks.
If your boat is usually bottom half of the fleet, even beginners will think about jumping ship after half a season or so. Again, they have every right to look for a more competitive program if they're not learning from you. So it puts the pressure on to keep improving along with your crew.
Or, simply accept the fact that you'll be dealing with continuous turnover, and learn to enjoy the roll of entry-level race boat. You'll be doing the whole racing community a great service, and eventually there will be enough good crew who got their start on your boat so that a few of them trickle back down every week.
A note about safety: NEVER assume that your crew know how to swim! If you take strangers out regularly, especially in windy race situations, you should have an ample supply of high-quality life jackets, and you should insist that they be worn. You should also ask about swimming ability. Sometimes the question "if you all fall overboard at the same time, who should I pick up first?" is a better way to identify a weak simmer than to simply ask "can everybody swim?"
You also have to be especially cautious with other hazards. Beginners may not have any idea what "Jibe Ho!" means. Always keep one eye out for the crew's safety, and don't hesitate to order them into the cabin if that's what it takes to keep them out of trouble in difficult situations.
The liability situation can be messy if there's an accident. Race crew have at times been held to be paying passengers, or compensated crew, and in either case this has far-reaching effects on your responsibilities as owner of the vessel. If they bring food, or if you supply food, or if you even buy the customary round of drinks at the yacht club bar after the race, the situation can be even more complex. It's best to arrive at an understanding that the status of race crew is exactly what it really is: they are co-participants in a competitive activity that has certain inherent risks, and that they recognize and agree to assume these risks, regardless of the voluntary exchange of food and other items of relatively little value (winch handles).
A guest book for crew to sign, acknowledging that they understand that they are neither paying passengers nor compensated crew, might be a very worthwhile thing to maintain. And it's also a record of their names and phone numbers, vital if you want to call them back for more racing. This written agreement of course does not absolve you of liability, and it would be very foolish and irresponsible to race without adequate liabiltiy insurance.
After the race it's considered good etiquette to buy a round of drinks for the crew. It's not required, but it's usually appreciated. At the very least, make sure they know that they're welcome at the post-race barbecue. If you win a lot, handing over the trophy to the most junior member of the crew is a nice gesture.
If all else fails, one sure tactic for recruiting good crew is to actually join the Cal Sailing Club, and race the Lido 14s on Sunday mornings with the best racers in CSC. You'll get to know lots of racers and crew, and your racing skills will improve dramatically at the same time. Your crew will know your abilities and your limitations, and you'll be able to function as an effective team right from the first race.