problem with link in portal login page

hi friends,

i have read all the posts about customizing the login screen in the portal, but i have a detailled question:

i am new to portal (i come from ABAP R/3-side), and new to all the technologies behind it (JAVA, HTML, and so on.....):

i have to add a link into the portal-login-screen. when the users clicks on that a window should open with a html-file displayed (or a pdf which is opened). I want to put a documentation there, and tel.numbers for calling when there are problems.

HOW can i handle this ? i have downloaded the NW developer Tool and imported the logon-par-file. but i am VERY confused about the coding there, its all java and html, i have NO idea where i have to put my own coding there ;-((

best regards, Martin