I am launching my first web site. I am in the process of setting up google services: Google Analytics, AdWords, and Adsense.
I searched the web and could not find any information about what the best practice related to what account I should use to setup these services?
One account for all the services should suffice. You can add and/or remove users quite easily to restrict or give new users access should they need it.
One thing I usually do is create one master account for a specific webpage, then I tie it to my own, personal log-in that I use to access these services.
But it all depends on the setup in my opinion. If it is for private use only, I'd say one account should suffice. Google gives you access control if more are needed.