You know, I've been wanting to do the same thing. I belonged to a church that had a knitting ministry. After one of the services, people would meet "under the tree" for fellowship and there was always a representative from this ministry there. She would have a table with signups, patterns and donated yarn.
There was always a message in the bulletin asking for donated yarn. When you signed up to knit a blanket, you would receive all the yarn you needed plus a pattern. Of course, you could always do your own thing but this was a great way to get someone started. The group met each week at the church to knit and fellowship.
I think that if you just put the word out and maybe set a time to meet, God will do the rest. Find patterns that work up quickly. Maybe you could even do a knit along where, at each meeting, the blankets would be exchanged and members would add on.
There are so many possibilities. Start simple. Invite some knitters into your home or maybe in your church hall (if you have one! we meet at a school). Talk together about your vision, share ideas. In no time, I bet you'll be going strong.
I can't wait to hear about your progress.
"Delight yourself in the Lord and He will give you the desires of your heart." Psalm 37:4