Bringing in ur  wife as dependent varies case by case..It's really difficult to bring her in OPT status..But still try garna ma kyahi bigradaina...Doc Needed
1.Ur Job offer letter with ur Salary indications
2.ur Recent Pay stubs.
3.Recommendation letter from ur employer(mentioning u can't work well without ur wife(sounds weird but i have seen couple of people making such kind of doc and getting the visa(
4. Ur Tax docs if any
5. Affidavit of support from u
6. Bank statement drawn from US bank
7. marriage cert
8. Bihe ka fota haru


Hope this helps

Please post the update if ur wife gets the visa..