Okay so I saw someone ask about how to switch game modes, so I'll make a simple guide on it.
This may not be as detailed as some other guides, but hopefully it will help you understand, and if not, just post here.
First of all, Find a game mode on like, Read around on the SA:MP forum, here's a link to the release section that will have some game modes.
As an example I'm going to use my custom game mode which can be found here
So first, Get the .AMX file and extract it somewhere, such as your desktop
You then want to drag it into your Samp Game Mode folder ,which can be found in the folder where you extracted all the files that were included in the server kit, which can be found at San Andreas Multiplayer :: Multiplayer modification for Grand Theft Auto San Andreas
Once it's moved into your GameMode folder the server will be able to read it as a game mode, but first you have to set it as the game mode, Which is the next step
Go back to the main folder with all the server files and open server.cfg with Notepad, There you will change the game mode, So where it says "gamemode0" is your current game mode, change it to the name of whatever the file was, if you're following me exactly with the GM I used, you just deleted the current one and type in FRGM.
After that just save and close, then run the server as you usually would, it should load the game mode you set
Hope this helps, and as a side tip, you add filterscripts the same way, just put them into the Filterscripts folder, and put the name of the filterscript into the server.cfg.