I just did my DIY solar install a few weeks ago (automated and all that) and agree with all above on the holes. I wrestled mentally with the idea of putting holes into a roof that does not leak. I discussed it with a roofer I know and felt better about the whole process after that. You can't make an omelet without breaking some eggs, so you'll just have to go for it. Buy high quality sealer and keep a couple of old t-shirt sized rags on the roof with you as you work. That sealer is very messy and I promise that you WILL need the rags. Goo Gone and GoJo work well for getting it off of your hands at the end of the day. I hear that laytex surgical gloves are a good clean hands option as well. (I just got dirty and used the aforementioned cleaners after the fact.)
Here's how you safe yourself on the roof: get a decent climbing rope for you and something adequate for your tool bag. Tie the ropes off to an immovable object (a tree works well) on the opposite side of your house from where you are working and take the rope over the peak of the roof so it hangs down on the side you need to work on. Tie yourself off with this (70's Batman & Robin climbing style). Use caribeaners to clip yourself in and make adjustments etc. so you can easily move around. Once you are secure up there it gets pretty fun. There's rock climbing sites out there that can show you how to tie off & secure yourself --it is really easy to do, keeps you safe, and frees up both hands and your mind so you can work efficiently and effectively. Now, for the cheaper grade rope, get yourself a tool bag and load it with all the things you may need up there. Pull it up to the roof and tie it off. You can use dummy chord on things you may drop and break (drills and such). You may want to use gloves depending on roof temp so you don't burn yourself. Having lots of pockets is a plus too..they come in very handy on the roof. Oh, and get good galvanized lag bolts, you don't want rust up there.
Now that you're tied off and safe, working with the panels on the roof can be a pain as well. You can preset them by tieing them off with ropes so you don't have to hold and drill at the same time. I did not have a helper up there, so I had to get creative on how to make it happen. I tied my panels off and pulled them up to the roof, then tied them in to my ropes to hold them where I wanted so I could align them, drill, and bolt. It went pretty smoothly. Basically, I pulled a page from some things I had been trained on in the past and applied it creatively to my project. Hope this keeps you safe and helps you out. I installed 5 each 4' x 12' panels this way. Oh, you'll need to use the schedule 40 PVC to connect it all together. Just get white pipes (unless you have black available in your area) and paint them black with the plastic formula spray paint for the pipes that will go on the roof. I cut and dry fit all of my pipes, then I glued my roof pipes in sections and painted them on the ground. After they had adequate time to dry, I took them up to the roof and installed them. I scratched them in some places so minor touch-up painting was all I had to do on the roof...simple to do. I initially made the mistake of using black ABS pipe to span a skylight and learned that ABS is a bad choice...the hard way. There's always time to do it again...the right way. Good luck with your install.