Ben,
1) By the cache=200Mb, i meant the cache on your firewall/gateway pc. You should have one; I use Smoothwall, which is free and excellent. A similar one is IPCops. There are commercial ones. All will offer interent caching,99.9% using squid. It acts just like the Temporary Internet Files in Windows. All PCs on your network will use this cache ... you force this on the firewall. So, 1 x 200Mb is all you need....it could be 500Mb, it is up to you.
2)The network drives I talk about are just places to store things. Nothing 'runs' there. SO, as long as you have a WIndows readable drive (eg Samba) you can use it.
If everyone uses, say, Copernic as a search engine, then install it on your user pcs base setup using a network drive as its default directory. eg install it on G:\copernic. Give evry user an icon on their desktop to use it. Make it read only on G:\. Generally, make G: a read only drive, so users can load and execute the programs but not delete or alter them.
You can run MS Office from there, but you need to make 2 changes to where Office stores files:
a) set the user's files to be on their home drive (H: or N: or whatever network drive you choose for them); Open Word, then Tools/Options/File Locations/Documents then highlight 'Documents' then click Modify.
b) Now Modify the location of USer Templates to be on the same Home drive.
3) You need to have a Home Directory for each user on your server. They have one created for them on SME server automatically. Use that. Have a login script for each user to run...it can be one common one. It should connect them to their network drives.
eg
net use g: /d {get rid of old drive mappinga}
net use h: /d
net use g: \\sme-server\group {set up new ones}
net use h: \\sme-server\%user%
{%user% is a windows variable containign the username for the current logged on user...check this, cos I am working off a dim memory}
This is a very basic mapping of two Windows drives to 2 folders on the SME server. You can get fancier login scripts which disconnect the g: and h: (or N: whatever) when they log off. Do a Google search on Windows login scripts. (logon scripts??) for extra help. Windows 9x PCs have a slightly different login script method than WIndows NT/200/XP. In other words, the PC automatiaclly will look for a login script, but where it looks depends on the OS of the PC.
If in doubt, get hold of a Samba Howto, or as a last resort, get hold of a WINdows NT text (cheap!!!) which can tell you about logon scripts. WIn2000/WinXP Servers handle it differently and are probably a bit too complex for what you want. Once again, do a Google for Smba and Windows Login Scripts.
Cheers
Ian