Strategies used for licensing 'try before you buy' software on networks

Hi

I wondering what strategies software writers use regarding how they make the
people installing the software (Network Engineers etc ie all of you
hopefully! ) license their software. I am in the process of creating an
installation routines aimed at win98 servers up and would like it to be as
easy as possible for those installing it.

I intend to offer a package so that the software can be assigned to users
with AD OSs and a normal installation routine for pre AD OSs

Hopefully as you have experience of installing software you may be able to
answer some of these questions:

1) Is it ever required for every individual user of the software on the
network to enter the release key?

2) Is software normally installed on local machines or on servers?

3) When software is installed using packages, are you ever required to edit
config files first?

4) If you are required to edit config files, what kind of data is required?

Many thanks to those of you that take the time and trouble to answer some of
these.

Thanks
J