beginner question about how to correctly do PCT

I am trying to figure out how to correctly do my PCT. I have a couple questions. I am on dianabol 30mg/day and test propionate 1cc every 3rd day.

1. first off, on the resources page here i viewed the page telling how long to wait before you begin the PCT for each different substance. well for d-bol it says 24 hrs but for test prop it says 3 days....how long should I wait?

2. also, at the end of the novice cycle #1 it shows the clomid therapy to look like this:
Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7
Week 1 300 mg 100 mg 100 mg 100 mg 100 mg 100 mg 100 mg
Week 2 100 mg 100 mg 100 mg 100 mg 50 mg 50 mg 50 mg
Week 3 50 mg 50 mg 50 mg 50 mg 50 mg 50 mg 50 mg

Im guessing that IS the PCT?? correct? is that a good way to do it? cause I have heard people saying it should last longer than that. Do I need to include nolvadex in my PCT?

3. finally, this question is by far the dumber one included in this post but hey Im new....what exactly does clomid and nolvadex do for you? how do they benefit you? Is their purpose to keep the gained muscle on you?

thanks for your time.

start 3 days after last prop, run 100mg/ed clomid and 20mg/ed nolva for 30 days