The following is a bit of information about how I run PbP games.
I expect that players will be posting at least once a day, if not more frequently. Typically, I will use the "Rule of Three" - where if there is a non-combat decision to be made, I will move on to that when three people (or half) have agreed to go in a certain way.
In combat, I will be posting a "combat tracker". This will show who is up, and status of all combatants.
Please make sure that you have your character sheet up to date on the site, and that you have a tagline that shows your current status. My preference is to use This Template (just make a copy to save in your google drive, that's the easiest). This is the best way to make sure you are getting the benefit of AC boosts, etc...
Generally speaking, if there are knowledge or other checks to be made, I will add the rolls to a post, spoilering the information that would be learned. Until proven otherwise, I assume that the players are adult enough not to mix "player knowledge" with "character knowledge".
The following PC rolls will always be made by me to keep things moving:
Further, I may make a roll of any kind on your behalf if you do not post within the 24 hour timeframe (see above fore more on this).
Finally, a convention I have adopted (mostly for rolling during combat) in PbP games that I run is as follows:
1. No rolls during combat for any checks that do not specifically require an action unless called for by the GM. Same for free actions that do not influence combat. Eg. Knowledge (dungeoneering) to identify that ooze is a free action, but this is a roll you must ask the GM to make for you (unless he has asked for it). Concentration check to cast a spell is a free action, but that's fine to roll yourself (since it forms part of your cast spell action).
2. Always roll for actions in the order in which they occur. When in doubt, roll reactions to GM first, reactions to players next and then your actions. This should help minimize players swapping over save throws for attack rolls (and the like).
3. If you do want to make an "actionless" skill check, ask the GM to roll it for you. He'll have to post to tell you the results anyway.