Single user -> multi user

Hi

I have developed a reasonably siezd (70 Forms - 20 table relational
database) stand alone application using Delhpi 3 Professional. (A
customer record / transaction datanase inc. digital images of customers +
scans of their ID).

I now need to make it multi-user, up to 3 or 4 networked PC's under
Windows 95/8.

Having never developed network applications before I have a few basic
questions.

1) Do I need to / is it worth upgrading from D3 pro ?
2) How difficult is it to take a single user app to multi-user, and what
is basically required ?
3) Do I / my end users require anything extra than a couple PC's running
Windows 95/8 and network cards ?
4) Is a seperate PC required to act as a server  ?
5) Will all my SQL queries still work or require modifying ?
6) Is there any good literature on the net I should look at / any good
books I should buy ?
7) Anything else I should know / consider ?

Thank you very much for any assistance you can offer,

regards

Jason Amos.

email: Jas...@crazed.demon.co.uk

PS If I've posted this to the wrong place, my appologies, please point me
in the right direction...