I went for the first time last year. If you want to have a great time, rent a car or drive there. So many towns around Phoenix have parks. There's ton of food and drinks in Tempe, about 5 minutes from the stadium. Also in nearby Scottsdale. They usually have some giveaway with you ticket.There are hotels near the stadium, but not many. Buy tickets early. Unless you want to stand in the heat all game, get um early. Don't go to the Dbacks at Papago, its an Arizona homegame and not a lot of fun. There isn't much of a tailgate scene, but we got hammered none the less.

I went two years ago and have already bought my tix for next spring.  I know you won't need a hotel with your RV, but others might, so here's a tip:  We got our hotel on Hotwire and are paying $53/night at a 4 star hotel in Downtown Phoneix.  If you're not super particular about what part of town you stay in, hotwire has great deals.  (The ballparks are all over the place anyway, so one neighborhood is just as good as another.)  I recommend hitting games at several different parks--it's fun to see the various sites.  I hear the Cubs stadium is lots of fun, so I worked my trip around that date this year.  The rental car tax in AZ is enormous as I recall--just be prepared for it.

I'd definitely get tickets in advance.  The tix at the A's park are already on sale, but other teams are having their on-sales in January, so you need to find out when each goes on sale.  

The absolute BEST place to have breakfast is in Scottsdale--The Original Pancake House on Camelback Road.  It is in the lobby of the Motel 6 and has a huge number of different kinds of pancakes and they are all delicious.  My friends and I are almost looking more forward to the pancakes than to the games!  

...if you can get to a game at the Brewers stadium in Maryvale, I recommend it -- especially if it's a weekday game. Since there are so few Brewers fans to begin with, you can usually take your pick of great seats (and it's almost like a home game, since most of the fans there are for the A's).  Get to the game early if you're into autographs or getting photos taken with the players -- it's a perfect place for both because of its layout, and we got some great shots with Crosby and Swisher last year.  

I also love the stadium in Surprise where  the Rangers and Royals play...it's new and gorgeous and looks like an old-style grandstand, but unfortnately you have to take a very traffic-prone 2 lane road to get out to it.

We've stayed at the Doubletree Guest Suites in Phoenix both times we've gone, and although it's pricey it's quite a treat because it's the A's team hotel.  Not all the guys stay there, but it was fun to be swimming while Huddy (sniffle) and his little girl are playing in the pool or find ourselves eating breakfast next to Wash.

One thing I'm hoping to do this year is to get to some minor league games at the Papago complex that's a mile or two from Phoenix Muni...I believe those games are free, and there are lots more young A's I'm looking forward to seeing this year.

Nah man, not free.

Usually around January MLB or someone releases a Spring Training guide that you can find at any bookstore for around $10 bucks. It will go over all the team sites and trainging grounds and is a great resource to have for your travels.

I don't know how old you are, but if you have any intention of trying to pick up girls by pretending to be a ball player remember this... all the ballplayers pretend to do something else for a living. Seriously. I went a few years back with a friend who's cousin was a player, and when we went bar hopping he pretended to be a plumber from Australia. All the players did something similiar. Speaking of drinking, you've got to try a drink called the San Juan Hooker.

At the games, the yard long micro-beers are a must. Keep your eye out because the distributors bounce between stadiums.