Cabos is great choice! The vast majority of the resorts are between Cabo San Jose (CSJ) and Cabo San Lucas (CSL) on the Tranpeninsular Highway with the newest hotels and resorts springing up north of CSJ and south of CSl. CSJ is the older town with a much more artistic and laid back vibe. Lots of great shops and restaurants in and around CSJ. CSL has better bars and nightclubs (i.e. Squid Row, Cabo Wabo, etc.) if you are looking for that sort of activity. CSL has the better restaurants and a better entertainment district. Cabs are very expensive, so the further out you are from CSJ and CSL, the higher the price (everything is negotiable). I'd recommend staying closer to CSL if that's where you want to spend your time.
My wife and I go to Cabos just about every year (for the last 10 years). If we stay less than 5 days, we will go to town maybe 1 of those days/nights. The remainder we spend on property. I've stayed at the Westin and really enjoyed it; however, we currently stay on a private resort. I would also recommend looking at VRBO for villas and condos; nearly half of the residents in Los Cabos are Canadian or American expats - some live there full time but most simply have second homes. You can find some great deals on Villas and Condos in Los Cabos.
For your first time, I recommend:
The Office (restaurant)
Mango Deck (margaritas)
Cabo Wabo Cantina (ask if Sammy is working)
Edith's
Giggling Marlin (take the upside down shot)
El Farallon ($$$ but worth it; must reserve weeks in advance - see opentable.com)
Hire a driver before you arrive at airport - they will save you a lot of time, get you to your resort/villa, stop by Mega (or CostCo) and allow you to relax with beer and sometimes champagne enroute.
Mega (mexican version of walmart) - stop there to pick up beer/wine/food/water - will save you $$$.
If anyone helps you, they are trying to sell you a timeshare. Walk away! This includes the airport upon arrival - grab your luggage and walk through the "shark tank" until you're outside - do not stop!
If you golf, bring your clubs and pick just about any course. They are all beautiful.