I haven't done Netscape, but I'll give you a hand. You'll need to answere a couple questions for me, though...
What file did you download? .rpm or .tar.gz?
If it was some form of zipped file, did you get it unzipped?
Is there a netscape-installer or some-such directory now?
Is there a README in the new directory? If there is, it should tell you in there what you need to do.
I use Mozilla, and highly recommend it. Netscape released their source code a few years ago, and the Mozilla project was created. Mozilla coders then surpassed Netscape coders, and now Netscape is built from Mozilla code. Since they are still a commercial outfit, Netscape changed some options in the code to make it more profitable to them. I hear there is a bit less control for blocking pop-ups and whatnot, though I don't know first-hand.
Anyway, installing Netscape should be pretty similar to installing Mozilla. It downloads as a mozilla-blah-blah-blah.tar.gz . In my downloads directory, I run...
tar xzf mozilla-blah-blah-blah.tar.gz
...which unzips the .tar.gz file and creates a new directory called mozilla-installer . I cd into the new directory, and check the README. In the Linux Installation Instructions section, it says to run the mozilla-installer command. So, I run...
...and follow the directions. After that, Mozilla is installed.