For life skills check out the Casey Life Skills web page it needs to be translated for those who read things literally but it can be done easily. It is free and has a ton of free/low cost teaching tools. It works well with adults too. I know a lot about the tools and how to modify them for autism. Feel free to PM me. I have trained these tools nationally and am one of the only ones to use it (with the blessing of the creators) with populations other than foster care.

The book I make everyone who works with my son read is "Simple Strategies that work!" by Brenda Smith Myles, Dian Adreon and Dena Gitlitz. It is a 40pg quick read of pure practical ideas.
Temple Grandon also co-wrote a book about talents that is very helpful.

How restriced are you by school required materials?

The most important thing I can say is to keep it as practical as possible. Also, are these kids on deploma track or certificate of completion? I have a college degree (dual degree with honors) and cannot get/keep a typical job because of my aspergers. The degree keeps me from getting retail jobs that I could do well with as I am "over qualified". Skills portfolios can be more helpful than a typical degree.

Help them to learn as much about themselves as possible and how to advocate. There is no such thing as an IEP at a job. Also... push them towards jobs that pay a livable wage. I followed my obsession areas and they don't pay enough to live on.