North has worked for ESPN since 1993 after a career in which he won the US Open in 1978 and 1985, the latter victory securing his sole appearance in the Ryder Cup.
The 63-year-old failed to win a point from three matches as Europe won by five points at The Belfry.
"I'm certainly happy to have him on my side and in my ear and helping me bring the cup back from Europe this time," Watson told a press conference at the Greenbrier Classic.
"It's been way too long. We have lost seven of the last nine Ryder Cups and I don't like that. It's time to change the tide."
North and Watson have been friends since the 1960s and North said he had no hesitation in accepting the role when he was asked earlier this year.
"It's obviously an honour and we will do whatever we possibly can to get the cup back here where it belongs," North said. "My wife and I usually get down to Kansas City (where Watson lives) two or three times a year and we were sitting around at dinner when Tom said 'Hey I got something to ask you. Would you want to be my assistant?'
"I said 'of course'. It took me maybe a second and a half. He didn't get it out of his mouth. I was absolutely giddy over the opportunity to not only hopefully have a role to get the cup back, but also to be able to help a dear friend.
"If I can take a little bit of the responsibility off his shoulders and make it an easier week for him that will be awesome for me. I am looking forward to it. The Ryder Cup means a lot to me. I get emotional covering it and the bottom line is that we get a 'W' at the end of the week.
"The one thing I do bring is a lot of experience of being round these players and hopefully I can help Tom get a good grasp on some of them. I'll do whatever the captain wants me to do.
"The most important thing is if he asks me a question I give him an honest answer immediately. You don't have time to sit down and go through 45 different scenarios."
Watson will be 65 at Gleneagles and spends most of his time on the Seniors Tour, while opposite number Paul McGinley is still playing on the European Tour alongside most of the players who will make up his side.
But Watson can draw on the experience of winning the biennial contest as a captain once before, when he led the United States to a 15-13 win at the Belfry in 1993.
"I've been watching a lot more golf on TV, how they are finishing when the chips are down and the pressure is high," the five-time Open champion said. "You can see a lot by looking into their eyes I think.
"My job is as a stage manager and the actors go out and they perform. I will have my assistant stage manager Andy North and maybe a couple of players to be named later and that's what we're going to try to do, set the stage perfectly for our players to go out and perform their best.
"I have a few tricks up my sleeve. You are not going to have the luxury of all 12 players playing to the same level, but as a stage manager you're going to say 'I know you can do it, just dig deep and get it done'."