For controls and features read the ReadMe as that contains all the information you will need. Installing modded cars will require OpenIV (google search it), adding scripts has always been a drag and drop feature, just read the readme's with each one for more information, but as a rule of thumb all scripts that are .net.dll go in to the scripts folder and all .asi scripts will go in to the root folder (the one with LaunchGTAIV.exe) and the corresponding .ini files go with the main script file. All ELS cars should be compatible, but mod authors will specify if their cars are ELS8 built. EFLC is Episodes From Liberty City, basically an expansion pack on the game adding more car slots. And as for tips, just enjoy the game and the company, if you ever need any help you have come to the right place.