You can check for updates here:

http://www.fs.fed.us/r9/forests/allegheny/recreation/hunting/

Also, if you filled a DMAP tag on the ANF last year and properly reported it then you might just get a packet from them asking if you want to participate agian this year. In this case you'll have the opportunity to get your coupon before applications become available for others. This is how it worked last year, but I don't know if they're doing the same this year or not.