my macbook operates on OS X 10.6.8 Quickbooks needs OS X 10.7.3 is it ok to upgrade to that operating software?

On that Mac model, yes; it's likely better to upgrade to Mavericks instead. In either case, back up your data and check your applications for compatibility first.

(103718)

If you have atleast 2 GB ram iinstalled you can do it. BUT you should be aware that many older applications are incompatible with 10.7.

Go to this site to check what you have against the compatibility table:

http://roaringapps.com/apps?index=a

If you have incompatible applications that you need to use the only option is to pay for upgrades to a compatible version.

https://discussions.apple.com/docs/DOC-6271 will cover more about application compatibility first. And backup your data before installing anything.