I am basically the only Christian in the house?

First, you need to find the leader of your church and discuss it with him/her. I'm sure that they will be willing to help you in any way possible, next, you need to pray and pray and pray! God will answer your prayers and He will give you the words necessary to talk to your family! Thirdly, I would say that you try to get your brothers to go to youth group with you...it's not quite as formal as a church service and so they might be willing to go. If not, then just plant the seeds in them and let God do the rest, He will succeed! :)