TDC is overrated. I just rotate the engine (in the proper direction, like erik said) until the valve I want to adjust closes, rotate a bit more, then adjust it. Valves are either completely closed, or open, they don't stay partially open for any length of time. Even the vtec-e valve will open slightly when you spin the engine, be sure it closes - then adjust. I also agree - you don't need a fancy tool, box wrench and screwdriver will do fine. Good luck.
Years ago when I did a valve job on Rusty I adjusted the valves while the engine was idling with the valve covers off. The valves were perfect the first time, but there was some spillage onto the exhaust manifold that burned off over the following day or so.
Jay, American V-configuration engines can (and some should) be adjusted while running since the adjuster is also the rocker arm retaining nut and doesn't move with the rocker arm. Hondas and other imports carry the adjuster on one end of the rocker arm itself (usually right above the valve), and can't be adjusted while running.
Replacing valve cover gaskets is always recommended, but I can say that I've gotten lazy or forgetful a time or two and if you clean everything thoroughly you can get away with re-using them once depending on the age. I'd consider this more of an emergency repair or last resort (say if the dealership and parts store are out of gaskets for example) than a normal work practice though.
Unless you break it taking it off, or its brittle, I would reuse the valve cover gasket. I've had my valve cover off twice and reused the same gasket without any leaks. I agree it isn't ideal, if I had a gasket set I would use a new one, but on a Honda it usually works.
I've only ever worked on American vehicles. Most were GM V6's & V8's. The closest to foreign cars my family had were Chrysler K cars. I think some of them had Chrysler engines, and I think my Mother's old 1988 LeBaron had a Mitsubishi engine in it. I never had the valve covers off of that LeBaron though. Tough little car. Mom had almost 200,000 miles on it when she sold it, and she sold it to her best friend's son who put another 100K+ on the car till he totaled it.
No problem. I wasn't trying to be snippy or anything. Just making the point so some of the less mechanically inclined viewers wouldn't get confused (Imagine trying to adjust valves when the adjusting screw is bouncing up and down 15 times a second!)
FWIW, even though I've owned an american car or two, I've only ever made valve adjustments on my foreign cars which have to be adjusted off and cold...
Oh yeah; domggg, make sure that when you adjust your valves the engine is stone cold.