LoDivaLoca,
Disneychrista said it all. If your dates are set and you are ready to finalize your accomodations then go for it. Personally, I'm amazed at the people who secure great deals on priceline for reservations 8-10 month out. That's too far out for non refundable for me. Anyway, for our trip last feb, I started bidding in October. No luck for 4 months (Bid $60-$73 for Resort level) Finally, on Jan 30 (for a Feb 21-3) Reservation I got the Dolphin for $72 night. I was thrilled!.
How far in advance also might depend on when you're going. We going in October and whil I have some backup reservations I'm really holding out to see if WDW comew out with any room only specials. I'd rather pay $49-$55 for an All Star Resort for a couple nights, than take a chance at being off site at a resort level for $60 (plus resort fees, etc...)
Spend some time reading through the bidding for travel site, decide parameters, make a back up reservation and go for it.
BTW, my general philsophy is that if I get information from a board, I try to post information in return. After all, the more people that post, the more hopeful the board becomes.