Last year I shipped a couple of snakes for the first time.
I used Ship Your Reptiles for it. They have kits you can order that contain everthing you need. If you aren't sure what size kit to get, email them, expain the situation, and give them the weight of your snake(s). They'll tell you the correct kit to get.
If you follow the instructions you get with the kit, or ask for help on this forum, it should be a fairly easy process for you.