Recommended way to Install Application so all user accounts have access to it

Hi,
I am new to the Linux world of doing things - Mandrake 9.2 so please bear
with me.
I do have a problem I hope will be resolved in this newsgroup - It involves
setting up Netscape for all users.
I have set up user accounts(adm,ctools,ntools,rpm etc) for my daughters on
my Linux box. However, I'll like to set up Netscape so that they have
accesss to it when they log on. I thought on installing three separate
copies (one for each user account) but something tells me that I am wrong
with this thinking.
Anyway, I went on and did install a 'local' copy for the first user account
and could not get Netscape to display a web page that needed the plugin. It
just crashed out. When I removed the link for the plugin I could get
Netscape to load the page and stay loaded without crashing out. I have
successfully installed netscape using root along with the necessary plugins
for the root account with no problems.
What is the recommended way to do what I am trying to achieve?
Any hints will be appreciated.
Thanks
Samuel.