Question
We are going to be mulching a large portion of our backyard for a playset, fire pit, etc.  We need to kill the grass first.  What do you think is the best way to do that?  Is it necessary to pull up the dead grass before mulching or can I just leave it and would you recommend laying down some type of black mesh material between the dirt and mulch?  
Thanks for your help!
Laura :)

Answer
This is a great question.
The simple answer is yes you can kill the grass and leave it. However, this grass will break down and can cause fungus and more rapid break down of the mulch above it. It is really best to get as much leafy organic material out first. I recommend that you kill the grass with any herbicide. If you want to do this soon, go with a 24 or 48 hour type killer. Round up is very effective but typically takes a week.
After it is dead you should cut it with a lawn mower set as low as possible. Or you can skim the grass off with a shovel.

Adding a weed barrier is not required but may be a good idea to curtail weed growth and stabilize the surface.

Good Luck.