I recently glued together two 1 and 3/4" thick by about 8" wide and 30" long oak boards to get 3" thick material to cut legs out of for a desk. I didn't plane the wood at all, and one board even had a slight bow to it (very slight, like 1/8" gap at MOST).
So what I did was placed the boards together so the bow gap was in the center of the boards. I applied a pretty hefty coat of glue to the bottom board and spread it out evenly in a nice thin (not TOO thin) coat covering all the edges (remember glue oozing out of the gaps is a good sign) and then I brushed a light amount of glue over the majority of the surface of the other board just to saturate it. I placed the glued faces together and used a lot of clamps and snugged them pretty good (not too tight as to void the joint of glue but snug enough to force some glue out of the gap and create a nice tight seal). I read another user post on the forums and he said it better than anyone "Remember, clamps are to hold the pieces in place, not compress them" because you don't want to tighten them all the way and void the joint of glue as I said before.
I like using pipe clamps because they get the best tightest most reliable hold I think. But any clamps really will do. Just place them at regular intervals and make sure you don't leave any portion of wood without a clamp so that part of the wood won't bow or separate during temp changes or anything.
For my board measurements I placed them about every 4 inches and I made damn sure to place at least 2 on the ends of the boards (i.e. the corners) and I didn't have a clamp wide enough to really reach down into the exact center of the boards so I used some C-clamps and just tightened them snug so I didn't leave marks in the wood. I put 2 C-clamps about 6 inches in from each end. Let it dry over night and I took the clamps out and cut the legs and there were no gaps.
I've read on here and I've learned from my own experience about how to face-glue boards together. I've done it many times and I don't see a problem with not planing them as long as you clamp and glue them properly.
***Make sure you do each board in separate glue-ups too. And at the end of the process you can use your hand planer to get a nice surface on the top and bottom of the final glued up board. for aesthetics.
Really long reply, I appologize but I didn't want to leave any question as to what I was talking about (that's why I gave you my example of how I did my project), but again this is my opinion and how I would do it I'm sure you'll get lots more feedback but I hope my reply helped or at least gave you more to think about. This forum has been good to me so I'm trying to give back and edge gluing or face gluing boards is kind of a strong point of mine.
"...Enjoy every sandwhich." -Warren Zevon