You should be able to install the cam first. Every rebuild i've done I have always put the cam in first reguardless.
I would say a good tip is to keep each valve/lifter/spring/retaining clip/rocker arm together from where they came off. So, the intake set of those on cylinder one would stay together, the exhaust set on cylinder two would stay together, etc if you'r not replacing any of those since they have a specific wear pattern. But since its already disassembled, oh well. And you should at least be replacing the springs anyway
Tip two would be if you can do a 3-angle valve job and re-grind the valve seats. If you dont have the tools/knowhow, see if you can find someone to do it. The valve job alone will make a noticable difference in the engine and where its not life or death important, it sure helps. Gives the valves a much better seal.
Aside from that...go slow, don't brake anything, don't cut corners, and be sure you put the piston rings in right!