Squirrel files are .nut files. They pretty much just text files and thus can be edited by any text editor, though the recommended one is notepad++
You can download it for free here:
http://notepad-plus-plus.org/Once you've downloaded and installed it download the
Squirrel for Notepad++ language file. Extract the .zip and move the file userDefineLang.xml to Notepad++'s AppData directory.
The AppData directory for Notepad++ is either:
C:\Users\your user\AppData\Roaming\Notepad++
or
C:\Users\your user\AppData\Notepad++
depending on the operating system.
When viewing a .nut file, if the program hasn't done it automatically go to the language tab at the top, click it and click Squirrel, which should be near the bottom.
Unlike PAWN, squirrel does not require compiling so you can just save the .nut file and run the server.
As a starting point I would recommend looking at this example:
http://liberty-unleashed.co.uk/VCWiki/Scripting/Squirrel/Examples/SQLiteReading through that a few times and trying it out yourself is one of the best ways to get familiarised with the syntax of both Squirrel and the in built SQLite features.
Another useful tool is the
SQLite browser. This allows you to create and sort through your databases. It can be easier than always using the SQLite script functions.