WELCOME WELCOME WELCOME! I'm so glad you found us. You're at the right place for computer scrapping info.
I print my CGLOs (computer generated layouts) on white paper, white cardstock, matte photo paper and glossy photo paper. It all depends on what look I want. For example, I did a gift album for my mom in a 4x6 format and I printed it on glossy pre-cut photo paper. But for my day-to day LOs I'll print on white cardstock or matte photo paper (I'll print a single 8x8 LO on an 8.5x11 sheet and trim). Sometimes I'll even mount my CGLO on a piece of colored cardstock before I put it in the album. To print 12x12 you can go to Walmart, Staples, Office Max etc. Or go to
http://www.aprilshowersarts.com/ to print too. There are tons of options when it comes to printing so just go with whatever feels right.
There are even more options when it comes to programs. I use Adobe Photoshop 7...which I actually don't recommend for newer computer scrappers unless they're familiar with the program. Lots of people here use Digital Image Pro, Picture It Platinum, Adobe Photoshop Elements, or Paintshop Pro. There are programs designed to create computer LOs like Scrapbook Factory Deluxe too. Ultimately, if you want a lot of freedom to computer scrap I recommend you go with a program like Digital Image Pro or Paintshop Pro. They're more user friendly than Photoshop7 but still allow you to create whatever look you want.
I hope that helps a bit. I think you'll find this is a helpful group so feel free to post all the questions you have. Again, welcome to SBB!