To answer your question
regarding horiztontal layouts (landscape) I know that Hobby Lobby has scrapbooks that are just for those types of layouts. They are set up differently than the regular 8.5x11.
I usually do layouts in 8x8 because they print nicely and can find some really cute 8x8 books. I also print 12x12 and put in the 12x12 frames. Those are the best presents. But lately, everything I have been doing is 8.5x11. Andrea a designer here has the best templates and come in the 3 formats I just mentioned. She is a fabotastic designer of templates. So that is a great place for you to start maybe.