that's a complicated question, and it depends on the strain of yeast that you use. I'll try to address it as simply as possible given that you're posting in the beginner's forum, but others might have more to add to what I'm saying.
Your yeast packet should have a temparature range listed on it, I'd pitch the yeast into 70f wort, then chill the fermenter down to the temp range on the yeast packet. If it doesn't have a temp range, post the strain of yeast and we'll figure it out. When it's nearly done fermenting, heat it back up to around 70f for a couple of days. that's usually a good time to rack to secondary. then once it's in the secondary, cool it back down to the recomended range, and then gradually cool it down to around 35f, a couple of degrees at a time. You can leave it there for quite some time before bottling/kegging