My family and I have been going to Arizona since 1992 (not every year, but a few of the years). We went last year and had a great time.
We went to two games at the A's park, one at the Giants in Scottsdale, one at the Rangers in Surprise and one at the Cubs called HoHoKam Park.
If you are deciding to go to the A's and Rangers parks, you have made a great choice. Those are two of my favorites. Scottsdale Stadium is nice too...with the best food selection. I am not a Cub's fan, and didn't care for HoHoKam as much, unless you like the Cubs (which judging by your Card's avatar...you probably don't like them
Surprise Stadium is shared by the Rangers & Royals, and is by far the best Spring Training stadium I have ever been to. Great old-school design to it, freedom to roam around and check things out, sit out in the grass, nice location, good food etc. Nothing but good things to say about the Rangers home field in Surprise, Az. I went to a night game and had a ton of fun.
The A's park is also a cool one, it's pretty small and very low-key. It's set off in a desert background and a nice place to relax and watch a game.
As far as seeing players and getting autographs, I would guess the A's park is a good one, since it is so small and intimate. However, at Scottsdale (home of the Giants), we sat on the 3rd base side (last row...at the top of the bleachers)...and if you turn around you can see the parking lot. All of the Giants walk through to get to their cars, and this is the best place I have seen to get autographs. My son got Marquis Grissom, Omar Vizquel, Michael Tucker and JT Snow to sign there.
Lots of great places to eat in Scottsdale too. A place called The Pink Pony where they have lots of old baseball memrobelia, and another place called Don & Charlies that the players hang out at after games. If you have any questions I can try to answer more, but I love Spring Training in Arizona. Hope you have a great time.
"Candlestick made me a man" -Will Clark
"Real Giants fans loved them BEFORE and AFTER Barry Bonds came along"