I think with most airlines the soonest you can book is 11 months out. Is that February vacation week? If it is, I would book asap. I know we went a couple of times during April vacation week and flights out of Boston get booked very fast.
If your looking at Feburary of 07, I would suggest getting really seriously looking around August or September. The airlines are so hard to tell, but usually, you will get a fairly competitive quote at that time...
Most airlines should already have their schedules out for that time frame. SW will release theirs whenever they are ready....you never can tell with them. Right now you can book through most of October with SW...so it may be 3-4 more months before SW releases their February schedule. Many times I get frustrated waiting for SW and I end up booking with a different airline. Good luck!