[FlyingShark]

OK, first of all, I'm only in this for about 1,5 year and there are still things that I don't get very well myself. I'm gonna try to explain the basics of your question to help you on your way but keep in mind that there's a lot more of things to discover in modding. And also this, ALWYAS MAKE A BACKUP OF YOUR FILES BEFORE CHANGING ANYTHING. Otherwise you may (read will) have to start eaverything all over again serveral times VERY FRUSTRATING.
Now onto your question: How to manual install new planes:

-Download
-Extract to a seperate folder or on your desktop
-Put the folder with the name of the mod in your MODS folder
-Open the readme and start copy/pasting the wright lines in the Airini file and the ru properties files.

You find the airini file in your MODS/STD/COM/maddox folder
You find the ru properties in you MODS/STD/COM/i18n folder
You can open the ru properties with 'Open with" --> Wordpad
Mostly you will read in the readme file witch foldername to create in your Paintschemes/Skins folder (Never works with me though) if you on your turn find out how it works, let me know please.
Always read the readme files.
Always read the topic of and the topics below the announcement of the mod you want to instal.
Read the discussion sections.
Good luck.