Need Ideas for Making Mixed Ability Classes Effective in Instructional Delivery

I just learned that I will be teaching a class with three different levels of English in it:  beginners, intermediates, advanced.  Each level must follow an assigned curriculum (along with required benchmarks).  The total number in the class is 28.  I have 5 computers hooked up to the internet also.

I have planned for some whole group activities to build classroom spirit as well as language skills since the stronger students will naturally be assisting the weaker ones.

What I would appreciate is gathering some  ideas on  how I can  best pull off this delicate balancing act without neglecting any of their language needs?  The workshop I attended at the district office offered information on learning centers, but how does a high school teacher do centers with so many students?  I wish they had offered practical suggestions from colleagues who teach in grades 6-12, but that never seems to happen.  I don't want to just hand out worksheets to two groups while I work with the other.

Any practical advice you can offer would be much appreciated.

Denise

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