Are there any best practice guidelines for field names?

I've not see any "best practices" guides as far as a naming convention goes. In my experience, however, it has a lot to do with who will be utilizing the application and the purpose of the field. One standard that I - and I know some others - tend to stick with is using XX in front of a field name if the field is no longer used and you intend to delete it.

Other than that, I would suggest talking to the leaders within your stakeholder groups and try to come up with a consensus for what will work for your team.