Hey CP,
If I were you, I'd subscribe to FBG. I may be wrong, but you appear to lack a little experience in dynasty leagues and maybe FF in general, even though you mentioned you have played. The reason I say you should get a FBG subscription because they have lots of information on who you may target on the WR, who is upgraded/downgraded for the week and has a 250 going forward. There are also articles and projections that are dynasty based.
If you do have one already, then you should go and take a look at this stuff. There are also some dynasty topics in the shark pool you could probably dig up if you search for them.
I'll post a couple things you could do or things I've found successful and answer a couple of your questions:
How do you choose what players to start or bench? This is the NOW part of dynasty. Dynasty is long term but for your weekly games, you have to start who you think is going to put up the most points for that position. If you've played FF for a few years, this concept has to be familiar to you. Obviously bench the guys you don't start.
Waiver Wire- Waiver Wire is crucial, especially early in the season in all formats. We all like to think we're better than what we are, but there's always a gem on the waiver wire after weeks 1 and 2 at some position.
So you look at those guys and use your best common sense. Is the guy that went off the real deal or was it a fluke.
For example, I'm more inclined to think WR Royal from Denver is the real deal in dynasty than say Michael Pittman who ran in 2 Td's inside the 5.
Given the fact that this is Anthony Fasano's first chance to really play away from Jason Witten, I'm more inclined to pick him up over TE David Martin.
As far as your bidding goes on the WW, that's tricky. First, it helps to know your competition. If you're familiar with your league, you know the guys who will go crazy for a guy, good or bad.
The bottom line is you have to form some kind of solid opinion one way or the other on players and if you believe a certain guy is "your guy", then go for it. Just about every year there's a guy or two that's claimed off WW that helps a team make the playoffs or win a championship.
I find myself bidding more during the start of the season, and as the season progresses, you will see owners not pay as much attention, so it's then when you don't bid as high.
Personally, I think starting off with 2 dynasty leagues is a little much. I know some guys are in a plethera of dynasty leagues but I'd only recommend that when you're the guy answering posts about dynasty leagues. Remember, it's not the quantity of how many teams you have, but the quality.
If you frequent this site often, you'll find some posters who often post about rookies/dynasty so pay attention and ask questions. As anything you read, don't believe everything you read, challenge it in the appropriate way, it's OK.