Good choice Rich!
Something for everyone there. The new airport terminal is open now, so you'll have the pleasure of not having to fly in & out of the old "terminal".
The Cork Jazz festival is usu on in late Oct, as is the Kinsale Gourmet festival - worth checking out.
The Beara Peninsula has stunning views and scenery - if it's a clear day! If it's walking you're after, The Beara Way is a marked set of walks around the peninsula that starts in Glengarrif.
If the weather's wet you can put in a nice few hours wandering around Cork city - have a look at The English Market and there are loads of lovely restaurants (and lively pubs) about.
You're likely to hear phrases in Cork that you'd never hear anywhere else in Ireland - e.g.
"c'mere" = excuse me
"like" - this is just thrown into conversations all over the place
"bhoy" - means boy, but again, used a lot at random
"i will yeah!" = no
"how bad" = that's great
"yer wan" = that girl
"yer man" = that man
"pig sty" = Garda (police) station
"gammy" = deformed
"gimp" = idiot
"langer" = drunken idiot
Anyway, good luck - and remember, no such thing as bad weather, just bad clothing!!