Mike,
My son and I dove PV in August of '06 with Pacific Scuba. I'd recommend them. They have the fastest boats, too. One day we were the only 2 people on the boat. For beginners I'd recommend sites close to shore like Los Arcos and Majahuitas. Boat rides will be about 35 minutes but the water is fairly calm and current was non-existent. The boats are small without much shade. A shorty wetsuit was sufficient in August. There were lots of puffer fish, but not much diversity. There were a lot of stinging jellyfish at one site so I'd wear at least a dive skin. Depths were generally less than 70 ft. One lady freaked out when she kept getting stung and I thought she might have to be rescued. It's not a great dive destination, but if you're there it's worth diving a day or two. I also dove the Marietas, which is way out in the bay, but I wouldn't recommend it for beginners. The water was very clear and there was lots of fish life, but the current was so strong it ripped my snorkel off and pulled the regulator out of my mouth. We also swam through a 50-75 foot cavern located at 90 ft. It's about an hour boat ride.
Keep in mind that Mexico is not as litigious as the US and the liability is on you. Tour operators in PV will let you do anything you're willing to pay for and if you get injured or die it's your problem. My son and I took a 4 wheeler tour up in the mountains one day. It was one of the most stressful things I've ever done. We drove a 4 wheeler through the downtown PV traffic, we were chased by dogs near the landfill slums and attacked by a wild bull while going up a one lane mountain road. We wore baseball batting helmets and wore bandanas over our faces to keep the dust out. Thank God my wife wasn't there. She would have died from sheer terror. There were more ways to die on that trip than any dive I've ever done. I'd also avoid any great deals on snorkel tours sold by the beach vendors. Some of our friends made that mistake and ended up on a slow boat full of drunks with only enough snorkel gear for half the boat (when your done snorkeling, give your mask and snorkel to someone who hasn't been yet.....)