Migration Assistant

I used the Migration Assistant already installed on my new iMac to transfer files from my PC to my new iMac. It automatically created a new user account in which it dumped my transferred data (photos only), separate from the user account that I had established when initially setting up my iMac. Both user accounts appear to be administrator accounts. Is there any way to merge the contents of the new account that was created with the initially established user account? Also, if I use Migration Assistant to transfer other data, for instance, my documents, from my PC to my iMac, will Migration Assistant once again establish yet another user account for the new transferred data? Lastly, in attempting to find any support information regarding the use of Migration Assistant, there does not seem to be any support information out there in Apple Land --- is it because no one uses Migration Assistant? Thanks