honestly, the thing that I reccommend if you want to do it yourself is to buy a subscription for your vehicle at
www.alldatadiy.com. It's factory repair information will most likely give you the most clear instructions (usually includes some diagrams) that you can rely on. Even if you buy the subscription and look over the job and find out it may be a little more than you want to tackle....the subscription will still be very useful to you I think. It will list for you all the factory service bullitins (TSBs) for your vehicle as well as recalls. It will have accurate wiring diagrams and component locators as well as factory specific repair information and specifications. It also has labor times which will be helpful if you think that a repair shop may be trying to rip you off or something.
I don't know of any sites that give good instructions on how to do the job, but they are probably out there. You might search through a few forums you can find you never know when someone might post a link to some geezer's page who had nothing better to do than document step by step how he replaced the wheel bearing on his van...and take pictures as he went.
As far as job difficulty, I don't think it's a very difficult job, but I worked as an auto mechanic for 5 years so that is in comparison to some of the "hard" jobs that I did have to do. I would say if you are an average Do-It -Yourself-er and can perform such tasks as brake pads, oil changes, and maybe even a valve cover gasket or two then you can probably do this job with the help of some decent information. I do NOT recommend haynes or chilton manuals...about the only thing I have ever found them good for is an occasional quick reference in the specifications section or, if you're lucky, they may have a decent wiring diagram or two (though most say something at the bottom like "dodge caravan 1965-2004: TYPICAL engine wiring" or some crap like that....as if it is all just going to be the same).
Anyway, let me know if you have any other questions about it and I will try to help as much as I can.