I use Linux all the time as my main desktop OS and love it to bits Now for the questions...


A few questions:
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In Xwindow (I usually use KDE):

1. How can I change the login screen background (similar to c:\logo.sys in win98)

Right click on the desktop, go to "Configure Desktop" and you'll see wallpaper options there.

2. Where can I find Xwindow Themes for Linux

http://www.kde-look.org is a good starting point.

In Terminal sessions:

1. I use the command Lynx to browse threw internet in a terminal session, but how can I display/download/save images in it?

You can't, Lynx is a text only browser.

Once it would be saved somewhere, there must be a way to display the image using a terminal command who can show a picture pixel by pixel or something...
Absolutely no idea, you'd be far better running an XWindows terminal session instead.

2. I downloaded a program called Wine to emulate windows programs threw Linux, the Problem: It doesnt work...! I installed the package, but if I run the command "winelauncher" it says stuff about press the copy default stuff wich I do and then says error occurs... Anybody tryed that program?
Yes I have, and it takes a bit of work to get it going. Read the documents on installation and configuration at http://www.winehq.com. The command to run wine is usually "wine" as well, not "winelauncher".

3. How can I use a text editor similar to edit in dos in a terminal session
Use vi or emacs, depending on what comes with your distro.

4. How can I create some kind of batch file of commands (similar to *.bat in DOS)
With shell scripting. Have a look on google.