My first recommendation would be to look through the different forums and read the stickies. Here's the first one I would start with -
Why the Rottweiler is not for everyone.
When it comes to the yard situation, I've read that some members set-up an area in the yard and designate it as the dog's bathroom or potty area. I could've sworn that some members used something like pea gravel instead of mulch or grass.
Besides giving your dog physical exercise, you should know that this breed is very smart and needs to use their heads too (some say the dogs need a job). I've taken mine pretty regularly to formal training classes over the past three years. More when they were puppies and I was building a foundation. Less when they got older and I used classes as refreshers. Just last week my male and I attended our first Rally class. My female and I started another CGC/Therapy prep class last week too.
Why wouldn't you want to leave your dog inside when you're at work? Besides the horror stories that I've read about dogs being taunted, poisoned, even murdered, one of the things that ticks me off when I walk my dogs in a nearby downtown are most of the owners that leave their dogs out unattended. These dogs run their fence line, bark their heads off like crazy, and in general act like idiots.
I would rather have my dogs interact with the world at large under my supervision instead of leaving them to their own devices. When mine were little, I crated them inside while I was gone. That way they couldn't get into trouble and I knew they were safe.
When it comes to getting a puppy, keep in mind they're a lot of work. You've got to get through their mouthing, housetraining, etc. phases. If you decide that's the route to go, look at the different stickies and find a good breeder. Also, instead of making them hold their bladders/bowels all day long, think about whether your schedule will allow you to come home during lunch and take them out.