Your specific hand would depend on the stack sizes. In general, if you were getting better than about 2:1 on your call then you should make the call with just a flush draw with two cards to come.

As for helping with pot odds, your pot odds are just a ratio of what you are calling to what the pot already is. For example, if in a $1/2 game someone shoves $10 and it's to you on the big blind, you would be calling $9 when the pot is already $13 for pot odds of 13:9 which is the same as 4.333:3.

The way you use pot odds for making calls is that you compare your pot odds with the chance of making your hand. A flush draw is about 2:1 against to make with two cards to come, so if for example you were getting 3:1 pot odds from someone going all-in on the flop then it would be correct to call.