Yay! A maine coon! I have three kitties and my oldest is a maine coon who turns 3 on june 3! He is the reason I have three cats! i got him and then fell totally in love with cats in general. Maine coons have the absolute GREATEST personalities. It like a little person is trapped in their bodies! Mine is very large (17 lbs) and has very long hair. DiMa mentioned above that her turkish van's hair shortened up. My maine coon's hair has done nothing but get longer and longer (and also prettier I should add). Some parts of his coat are very near three to four inches long, including the hair around his behind! And yes, there have been several dingleberry incidents (including stray dingleberries that find their way out of the hair and on to my floor! Ewww!)
As far as my cat goes, he is also very immaculate about grooming. Cats are pretty clean creatures and are more offended by the whole dingleberry incident than you are. I dont really know of a lot of cats that like getting groomed and mine certainly doesn't, but i think his vanity makes him a little more cooperative with letting me clean and brush him. Usually he puts up a little fight at first, but once he realizes that I'm just taking good care of him and cleaning him, he relaxes. it like he realizes that I'm helping him out with that pesky stuff he couldn't reach, and then he seems grateful. And I am sure yours will be more cooperative too. But it might take a while- kittens are pretty squirmy anyway.
What ABSOLUTELY DID NOT WORK for me was a full-on cat bath. When my kitty, Action, was around 11 weeks or so, he started to really stink and the poor thing's back was getting all greasy because he just didnt really get the hang of the whole bathing thing yet. So we were naive, and thought he needed a good bath. I won't go into it, just know THIS DID NOT GO WELL. People always say maine coons like water. Although mine is curious about water, he does NOT like to get wet. I mean, he really thought we were trying to kill him. I've never seen such a panic. Don't even try this. Just stick to the wipes and as he gets older, he will get better at cleaning himself, and in the meantime, you will just need to fill in the gaps for him.
What has worked for me is a combination of the wipes (I buy "all natural" baby wipes from the grocery store. non-toxic and pretty much the exact same thing as pet stores, but less expensive and you get 10 times more), a small pair of scissors, and a good brush. And you can put them in the microwave for just a few seconds, and that will make it where its not so cold and shocking to him. Prince Charming will have a lot of hair and will also need to resign himself to getting a few uncool haircuts, especially around the backside. His hair will be so thick that this is often the easiest and quickest way to get the job done, and the most sanitary. You might have to cut out some mats in his hair too. No matter how much i brush Action, he gets real bad mats on his lower chest area where he cant reach so good, and also in his little armpit areas. The hair there is just so fine. As far as a brush, I recommend you have a slicker thats meant to remove loose hair, as well as a very fine tooth comb and a nontoxic detangler, which helps for loosening mats. Also, make sure the slicker doesn't have metal teeth. I had one, and it did work faster to remove hair, but i think it scraped his skin too much and made him uncooperative. Then i bought one with plastic teeth, and little beads at the end of each tooth. That one always gets a little protest once the brushing starts, but then he starts purring, so i think it feels good to him. That makes all the difference- how comfortable they are while you are doing it. And as cheesy as it sounds, when i groom my kitty, i whisper sweet things to him, so he sees the entire process as me trying to treat him, not restrain him. And timing is key too. Catch him when he's sleeping, and start by petting him, then ease on in to using a comb or wipes.
As far as the nibbling, as long as it isnt forceful, it's a sign of affection. He doesn't know it hurts. Same thing when they are "making biscuits" on you with their claws. Hurts like mad, but they certainly don't mean for it to hurt you. When a cat means to hurt you, or is acting out of some kind of aggression toward you, there won't be any doubt. If their love bite hurts too bad, a good thing to do is let out a short but tart yelp. Make sure its non-threatening. Its not meant to scare them off, just alerts them that it hurts you. And they will stop, and over time they will condition themselves to adjust pressure with teeth and claws around you. Make sure to teach your kids how to properly respond to this too, so they won't appear overly aggressive to Prince Charming. That just starts a bad cycle.
I'm very long-winded here, but I am just so excited for you and your family! If he has most of the common maine coon characteristics, this little guy will end up being one of the best pets you've ever had, which will be a great memory for your kids in years to come! They are a very interactive breed, and most of them will probably never be a "lap cat" but will always let you know that they appreciate you.
There are so few Diana's out there and I've never met another Diana Marie! Cool 
