I dipped into the online gaming just recently. The group has now done three adventures.
What I did was to get the email addresses of the players while they were generating characters initially. I walked them through the process explaining the differences at generation. I have a wiki on Obsidian portal which I also suggested that they check out. There were three things that I suggested that they look at.
I sent copies of the info to the email addresses to reinforce what I do often.
That being said, there were still questions before we started the game. We dealt with them during the first game and continue at times to deal with it.
Personally I wouldn't like pbp as it takes too long to accomplish anything.
Chat didnt have too much of a problem some digression but not too bad. When in combat rolled intitiative and they acted in order. I put up pm boxes to speak privately.
I have checked out gametable and it seems to work but it requires that all have the program.
hope this helps.