I have just recently adopted a 5 year old Boxer mix, and wanted to socialize her with my parents 10 year old male Am staff. The boxer Mix (Lady) was spayed almost 2 weeks ago, Max the Am staff has been neutered for years.
The first introduction was on Max's territory with in a fenced yard. They seemed tobe getting along fine, when all of a sudden Lady turned and started attaking him. Was this because I had started petting Max?
How can I do socialize her, will they every get along?

It will take two people, both of whom are recognized as family by both dogs. Socialize yours at your house with your parents, then have your dad out with you to re-introduce the dogs to one another. You and your dad should watch your own dogs closely and provide a quick distraction when aggression starts. I'm fond of an air horn or police whistle as distractions. After a few visits one person should be able to keep an eye on both dogs.

Lady was only spayed 2 weeks ago, I would give her time to heal first before introducing her to another dog.
It takes up to 6 weeks for them to fully heal after spaying, but they should be kept nice and calm for at least 2 weeks until their stitches come out.

I would do introductions on neutral territory... somewhere like a dog park or even just out on the street, that way there will be no issues with it being "THEIR" house.

Do this pretty much until they get completely used to each other and are happy playing together.

I like Cats idea of the airhorn and whistle. We usually keep a big blanket on hand just in case of any fights... throwing a blanket over their heads if they are fighting makes them stop 90% of the time because they can't see what they are fighting.

Ok well thanks guys! Just wanted to a quick update. Last night my mother and I took both dogs for a walk (it was an area that Max walks regularly) There was some tension, and I don't know if it came from me being paranoid because of the last encounter, but we were able to go for a semi enjoyable walk. We let Lady sniff Max, and Max was a perfect gentelman. Lady wasn't such a Lady... but happy to say no fights broke out, and both were rewarded with lots of treats and positive reinforcement. The people I adopted Lady from stated that she was temperment-tested with all different types of dogs, big, small, altered and un altered, and they say she did fantastickly. So fingers crossed, and hoping meeting # 3 goes even better.

That's great news Aurora!
I hope they continue to get along and become friends :)

Thanks! :)