Details are here. It looks quite good.
A while ago, I searched the online OED for illustrations of word usage drawn from Tolkien. There were about 150, which for someone who isn't Shakespeare is quite a good number. And hobbit is in the OED.
He also has his own adjectives: Tolkienian and Tolkienesque.
I still maintain the best book yet written on Tolkien (though I haven't yet read the one mentioned above) is by Tom Shippey (J.R.R. Tolkien: Author of the Century).
By the way, for those who don't know (for a long time I didn't): OED stands for Oxford English Dictionary. If you want to buy my friendship, a good start would be with a copy of the OED. Of course, if you look up friendship in the OED, the first example is from Beowulf.