Hmm... Not sure about track, mine updated only when I got my actual results in August, but I'm not sure what it's like for people already with results.
And Yay! Another Celticist.
There are definitely more germanicists than Celticists; Adam (my college Dad and the only other ASNaC in Catz) is one. Whichever choice you make, you can always pick one up in second year. Most of the time I wish I'd done Latin instead of Norse, so I may change to that next year. Or do a dissertation... Another benefit to Paleography is that you get to handle all the manuscripts from the Parker library at Corpus Christi, which include things like the Anglo-Saxon chronicle etc. But a lot of the course is covered in the other subjects anyway, just in far less detail. If you like doodling, then they give you lots of pretty Celtic pictures to copy.
BiscuitGirl; Yes, I would definitely recommend this process of course selection. Just because you like the sound of the course, doesn't mean you won't feeling like screaming at the lecturer every now and again ( I have this problem with Norse).
In terms of finding books, it really doesn't matter what you've read before you arrive. Most of the original texts are available in ebook format for free on the internet. The Celt database;
http://www.ucc.ie/celt/ is amazing for Celtic texts, not sure of what the Old english or norse equivalents would be though. I've found this website;
https://notendur.hi.is/~haukurth/norse/ really useful to help me learn Old Norse, especially as I can't keep up with the teacher.
I would definitely recommend that you read Bede's Historia Ecclesiastica (even if you aren't specifically planning on doing Anglo-Saxon anything) because he comes up everywhere. Try to read Snorri's Edda for Norse and the Mabinogion for Welsh. Dr Russell prefers the Sioned Davies translation of the Mabinogion, but the basic Lady Charlotte Guest (free version) is fine until you get here. For Irish, I would recommend buying "Early Irish Myths and Sagas" by Jeffery Gantz which is on Amazon for about £2.96. This is the actual translation you will be using in classes, so it's worth the investment.
Other than that I don't know if there is much else to recommend... If you have any questions on more specific books or other modules, I can ask around. The courses I do are;
Middle Welsh,
Medieval Irish
Old Norse
Gaelic History
Brittonic History
Paleography and Codicology
Keep smiling,
Rebecca.