Take a look at this thread: http://forums2.gardenweb.com/discussions/3119281/newbie-questions-about-composting?n=22 which addresses the questions you've got.

Are you still wanting to use it as mulch or are you wanting to know how to compost it now? If you're composting, mix it with other materials, especially browns if you can get some, to balance the high nitrogen content.

I often leave big heaps of grass clippings destined for mulch lying around a week or so, what with one thing or another that interrupts the process. They start to ferment, and shrink. But I put on a pair of gloves and go ahead and mulch with them anyway. Its best to orient yourself to be upwind.

I want to use it as compost now. Since i cut my lawn every week always have fresh mulch

Thanks for the read

Let me just put in a plug for mulching mowers. I actually don't even use a mulching blade, just let them fly out the side chute. If I mow in the right direction they're spread evenly and disappear back into the lawn in no time.