Since you want to have VS.Net (along w/ all the MSDN Library) on the HD
you may want to consider more space. But regardless, IMHO it's best to
make partitons that are reasonable in size rather than having humongous
volumes w/ large cluster sizes. But also, disks run best when they are
not too full - 50-60% filled is max for efficient allocation and future
defragability. I'd guess a 20-30 GB main partition would suit you, and
put the MSDN Library on a diff partiton along w/ other stuff that doesn't
change often (like your music collection).
Consider carefully how you partition initially. It's best to use XP Setup
to delete all exsiting partitons, and then make JUST THE ONE main
partition, and install XP on that. Then, using Disk Manager, make other
partitions as necessary. It's ok to leave space unallocated for future
use. HOWEVER, choose carefully how you make that second partition -
should it be a Primary (ie, bootable), or an Extended? It might be wise
to first make a Primary of, say, 20 GB and DO NOT USE IT (JUST YET), and
then turn the rest into an extended and allocate a chunk of it for your
next logical drive. Reserving the extra primary partition for the future
may be wise, you could use it as a recovery partiton (w/ second copy of
XP), or a Ghost/True Image boot partition. Since you have a second drive,
it would be a better choice for the Ghost Partition tho.
Google for "Partition" or "Partition Planning", or some such, there is a
lot of reasonable advice out there, much of it conflicting (of course!).
Good Luck.