does anyone have priority on the declare attacker step before attackers are declared. Example: can i tap a creature right before he declares it a attack but not on a main phase?
Yes, after the beginning of combat there is a chance for fast effects.
Short version is what jester said.
Long version is, if I'm not mistaken;
Main phase ends. Declare of attack phase begins. The active player has priority first if he/she wants to use an instant or ability now before declaring which creatures are attacking. Priority then goes to the passive (defending) player to use an instant or ability effect (such as tap a creature so it can't attack).
Then it moves to declare attacking creatures, with priority at the active player again. Then to the passive.
Then to declare blockers phase but I honestly am not sure which player has priority first on this one for instant speed effects (I think it's still attacker, as it's his turn, can anyone confirm?)
Then to damage phase, and then end of combat phase. And of course, during any phase, if an effect is added to the stack, it can be responded to.
Gorzo's got it. I laid it all out in another thread, le me see if I can {dredge} it up.
Edit: bumped it, check "Turn Phase Priority"
Also, priority always goes in order of Active then Non-active.
Active meaning the player whose turn it is.