Welcome, and good on ya, Scott. First off, there are manuals available online for many of the SOHC/4's. Unfortunately, I cannot remember where they are posted.
As for safety issues to check, I'll start a list. This won't be exhaustive; someone else will likely chime in with things I've missed.
1) Brakes: Make sure the front and rear pads are O.K. The rear brake should be adjusted properly. You may wish to bleed the front brake. If so, pick up a $15 SpeedBleeder bleeder screw replacement. Sizing information is in the Brake FAQ. With the bike up on the center stand, you should be able to test the wheels for free movement and quick stopping when each brake is applied.
2) Chain: Make sure the chain is adjusted properly and that it has not "stretched" beyond the service limit as shown on the adjuster. The chain should be properly lubed.
3) Tires: The tires should be free of cracks, have good tread and be properly inflated. If the bike has been sitting for some years, it is likely that the rubber has gotten hard and cracked.
4) Lights: Check all the lights for proper function.
5) Front Forks: Check the front forks for smooth travel. Look for signs of leaking fork oil.
6) Rear shocks: should not be very spongy. (Some smooth bounce is good.)
That's what I think of off the top of my head. The list may sound more intimidating than it is, and several of the items, such as the front forks, are covered by some state inspections anyway.
Good luck!
