The open ended straight plus flush draw is actually only 15 outs - don't double count the same cards
8 for the straight + 9 for the flush - the 2 we already counted for the straight = 15.
Regardless, in a multiway pot, you want to get as many bets in the pot as you can. The same goes for heads up, but especially multi-way. You'll play this differently depending on your position, who had the lead preflop, and so on.
For example, assuming there are 3 players in the hand and you are first to act:
-If you had the lead prelfop, go ahead and bet. If there is a raise, you should reraise.
-If Player #2 had the lead, you should check. He'll bet, #3 will call, and THEN you should raise.
-If #3 had the lead, you should bet, which squeezes #2 (and hopefully gets a call out of him), and then if #3 raises, you can reraise and really put the pressure on #2.
See how that's maximizing the amount of money going into the pot for each situation?
Top 4 sites can be found on my list here:
The just so happen to be the same 4 you listed...