Some tips I picked up while doing mine: Use a cardboard template to stick the timing cover bolts in as you remove them so you can remember where they all go, since there are several different sizes/lengths. Be sure to get all the bolts out, since some are removed from the back of the cover, and there's the one covered in a pool of oil. You can also use paper cups to hold hardware for each of the items you remove, such as p.s. pump, alternator, a/c, etc.
I was advised against the steel reinforced guides. As the chain stretches beyond the limits of the tensioner, it breaks the plastic guides and you hear the infamous rattling sound. With the metal guides, you won't be aware your chain is worn out until it breaks, and your timing cover and valvetrain go with it. If you really want to bullet-proof the timing, convert to a double-row chain like on the 22r. This costs more, but might be worth it if you plan on putting a lot of miles on.
You can do it without removing the head or oil pan, but I chose to remove the pan to make it a bit easier and to remove all the pieces of broken guides.
Finally, get a good timing set. Cheap autozone sets probably won't last very long compared to a Toyota or high quality aftermarket set like from LC engineering or DOA Racing.