I love Baja. I've been going there all my life, mostly to the area south of San Felipe.
A few years back, I took a trip to the tip, in a 1965 Land Rover 109, right-hand-drive, soft top. I'm sure I have pictures somewhere but the only ones I could find are these:
http://www.obtainium.org/gallery/9511_baja
I'm one of those people that feels like most of Baja is safer than the US. Sure, there are federales, young punk kids with machine guns; and crooked cops. But if you speak a little Spanish, don't act like an arrogant gringo, don't take anything that might be prohibited (no guns at all, no drugs of course, no expensive items, mellow on the overtly military gear) you should be fine.
In a modern rig, you could make it to the tip and back, but you'd be mostly driving. GN or Bay of LA should certainly be doable. Most of the major paved roads are about like a backcountry neglected 2-lane would be here, doable in any vehicle. The dirt highways tend to be washboard and will beat the hell out of you and your vehicle, but I do like the back road from (can't find my map at the moment) central Norte near Catavina to Puertocitos via Gonzaga Bay.
Gas is hard to find. Fill up wherever you find a station. Magna Sin is like standard unleaded here. Not sure how the prices compare to here lately, but I imagine they're about the same if not more. If you get less than 250 miles to a tank, bring a spare tank; but that said I made it with a 125 mile range and a few 2-galloners. Bring lots of spare water; 20 gallons wouldn't be too excessive if you're camping. Buy beer and liquor (I suggest Negro Modelo and Herradura, respectively) in Mexico; bring your water and all your other food with you because the grocery stores suck. Bottled water is fine to drink, as is water in most but not all restaurants. Most restaurants are fine to eat in; some are great, some are filthy scary.
AAA has a great map and a great book. Topos are really hard to find, tho there's one guy that does them if you can find him.
Get insurance. It may keep you out of jail if you have an accident. Don't have an accident! Drive slow - slower than the speed limit if you can stand it. Yes, it's really slow - why are you in such a hurry, gringo?
I'd (slowly) blow through Tijuana and Ensenada. Stop for lunch in Rosarita area. Aim for San Quintin for the first night. The rocks around Catavina are cool. GN seemed like a dump to me, but I guess there are whale watching tours around there. The east coast - San Felipe - is great, I tend to like it better than the ocean side. Haven't been to Bay of LA but I hear it's one of those "end of the road" sorts of places where people who go where the road leads them, drive to, end up, look around, and decide to stay.
I'd say you'd be better off not having an agenda, just spend half your time going south, and half north. I grew up in El Centro, so I'd tend to come home through Mexicali - maybe you can shower at my parent's house - maybe not.
Have fun!