What to Bring
Charter fleets generally provide all the tackle you'll need. Talk to them ahead of time to be sure they'll have what you want to fish with. If you book a hotel package that includes fishing with the hotel's fleet, you may not be able to speak to your captain ahead of time. In that case, you can bring the tackle you prefer or settle for what they have, which will likely be adequate but not always in the best shape.
For the best experience, make sure they provide or you bring:
Rods: Short stand-up-style rods, 30-pound to 50-pound.
Reels: Offshore-style lever-drag reels to match rods. 50-pound reels can be loaded with 50-pound line or 30-pound line. Two-speeds are best if you don't mind the extra weight.
Lines: 30- to 50-pound mono. 80- to 100-pound leaders and hooks should be available on the boat.
Lures: Baja fishing is live-bait fishing. Baits are $3 each in the harbor - tradition dictates you start the day with 10, then make bait on the fishing grounds with sabiki rigs.
Other: Bring your own gimbal belt and stand-up harness, and a scale for setting your drags.