Planning partitions for an install

[richard mullens]

I propose installing FC3T2 to a system with two drives.
On the second drive I would like to keep /home and my e-mail, and 
perhaps /usr/local

What partition(s) should I choose for my e-mail so that when I 
reinstall, from scratch (not update)
my mail remains intact ?  (Or must I back it all up anyway).

Would /var be an appropriate candidate for the second drive (so /var/www 
is retained also) ?

Thanks
Richard