Winston,
I would say that if you are just starting out on EASY and you are having trouble reading his sleepy cues, I would go ahead and start your wind down routine at the two hour mark. You can try that for a few days (w/ 2 hours of Activity time) and see how he does. He may be able to take a bit more A time than that. For my daughter, her sleep cues include rubbing her eyes, sometimes she will tug at her ears, she looses interest in her toys and won't make much eye contact with anyone (including me). She gets into a daze kinda. I think you are better off putting your son down a tad early than waiting too long and he gets overtired. Just experiment with it for a few days. It is helpful to keep a log of his days/nights. I still keep a daily log and we have been doing the BW thing for over 2 months.
With p.u./p.d. you will pick him up if he is really crying (not mantra or whining) and soothe him just until he stops crying. The minute he stops crying...put him back in the crib. He may settle, or he may cry again. You will keep doing p.u/p.d until he begins to soothe himself. Sometimes this can take 1-2 hours the first few nights/naps. My daugher is now at the point that me picking her up just makes her more mad (she is 6 1/2 months). For her it is better for me to lay my hand on her until she stops crying (and leave her in the crib). This methods works for us. You can adapt it to work for you and your son. You don't want to rock him all the way to sleep though. Put him back in his crib right after he starts crying. He isn't going to understand right away why you are doing this to him. You are having to teach him a new way to fall asleep. He will catch on. Be consistant and patient! It will pay off!
Come back with any questions or concerns and keep up the good work!
Shelby