My grandparents on both sides went to Yosemite in the 1920's. I attended SDSU for a while.
>I am a poor college student without a car
Get thee to a University Outing Club. During my numerous tenures at UC Berkeley, the Hiking Club never limited membership to students. Alumni, non-students, and hangers-on were all welcome. It worked really well for drivers and non-drivers because the paradigm was that "drivers don't pay" (since they cover capital and insurance costs) - all gasoline was covered by NON-drivers.
Edited to add: So if you're at SDSU, check out UCSD. And vice-a-versa. Also Harvey Mudd, Scripps, etc.
> Sneaky rainstorms? Do they materialize from nowhere like they do back east, or is a sunny forecast fairly accurate.
The weather forecasts should be accurate a few days in advance. It isn't New England, where, truly, "If you don't like the weather, wait 10 minutes." The summer is predictably warm and dry. The winter storms are large-scale events that you can hear about on the evening news. As you get to higher elevations, especially in the Sierra in the summer, remember, "thunderstorms require two things - heat and humidity". By late afternoon, there may (or may not) be thunderheads forming. Learn to watch the sky and learn to predict (for your particular elevation and RH that day), what might happen.
> Ferocity of micro-bears? I usually hang my food but i've noticed there are areas here with few trees...
I see many more grizzlies than black bears now in my status as a former-Californian, present-Alaskan. Brown bears and I have a lot of respect of each other and we have always figured out a way to head in opposite directions. CA black bears? I yell and run at them with a stick, intent on how much harm I will do to them when I get there. They are never there when I've run the 50 yards, having retreated into the woods.
> Bugs? People say they're not that bad, but I'd rather not find out otherwise when I neglect to bring a mosquito net.
I rarely carry DEET up here, but I'm a Hiker, not a Sitter or a Photographer and when I Fish, I go to Catch on the salt water, not be a Stander along a stream. If staying in one place around water at dusk, bring the smallest possible container of 100% DEET. If you are going to be hiking, don't bother.
> Water? Hiking in the desert seems like it might be different from the BWCA. Do you pack it all or can you find some.
Bring it all, unless you have great intel on reliable sources. There are places (Half Dome hike) that in every summer month of the even drought years, I know which springs are reliable. Until you get to that point or hook up with a really trustworthy buddy, err on the side of caution. Personally, I'd rather carry water in my belly than on my back. If I've pee'd in the last 2 hours, I've decently hydrated. If you can't remember when you last pee'd or if it was dark and stinky, find water or bail!
> Anything else that you locals may take for granted?
If you see funny-looking, medicinal plants, turn around and leave. If someone is acting like a street person in Manhattan, treat them accordingly. Expect more stable weather than you are used to.