APPRECIATE YOUR SUGGESTIONS FOR PREPARING DOCS TO INVITE PARENTS FOR A VISIT

Dear friends,
This seems an old topic for you who already been thru it. I used to see this kind of thread a lot but as we all know, we only pay attention to things that we need.
I am on H1 visa and I did not invite my parents during my gradaution. Now I want to invite them for a visit. What kind of documents did you send from here and what other documents is required to prepare at their end??

I am planning to send Personal Invitation letter, Bank Statement, Letter from employer, W2 forms. At their end, what other supporting documents can be prepared. Obviously, there will be a Bank Statement with reasonable amount, property evaluation.....but other docs i can't think of. Please help me preparing the docs or if you have the link to the threads related to this topic, please provide me that link.

YOUR SUGGESTIONS WILL BE HIGHLY APPRECIATED.

Thanks in advance.