I would start by identifying to some degree what area you want to buy in. Personally I know the Southeast Valley the best as I live in Gilbert and have worked the Southeast Valley for 13 years as a Realtor. Not that I don't know the other areas to a degree but if you had lots of questions about Sun City west I would need to find the answer for you. My greatest knowledge is in Chandler, Gilbert, Mesa, Queen Creek, San Tan Valley, Maricopa etc. The Valley is so large, not unlike Minneapolis. You wouldn't likely want a St Paul Realtor to help you find a home in Plymouth.
If you know the area you desire some then start with the tried and trusted who can you trust? Finding experience, trust, availability market knowledge etc will go a long way to accomplishing your goals. I would also want a full time Realtor.
I would welcome the opportunity to be included in your evaluation if you so choose.
Arizona Homes for Sale by a Guy from Iowa