I created groups in my yahoo account with all my contacts... Direct family, soccer players I coach, kids in my CCD class, wife's family, etc. these are handy when emailing, but I have recently found with my new android phone that I can view the contact groups when calling. This is nice as one of my groups is restaurants so it is helpful for reservations or take out. I can also quickly text a group of family members or athletes parents using these groups, email them, or create a meeting with them.

Does iPad give me the ability to use the groups I have created using yahoo or google contacts?

To the best of my knowledge the only service that will let you create and sync groups/labels with the Contacts app on the iPad is iCloud.

Both Yahoo and GMail can only sync the All Contacts folders, due to the limitations of the standard mobile protocols being used (at least that's my understanding of the issue).

If there are any third party apps that will do the job, I have yet to hear of them.