AN Fittings????

What the heck is up with them i dont understand them at all,i got my fuel cell in last week,now i need to sit down and order my Fuel pump, reg,line,fitler,and them stupid fittings that i dont understand!What do the numbers mean?And what do i need for a 3/8 alum. line?Im going with this set up - 16 gal. fuel cell,Cut off valve,filter,fuel pump,???,then up to my engine bay into my fuel reg,then into my carb.Hows that all sound?Help me out if theres a better way to go about this?Im gonna buy 3/8 alum line,should i use the line on all the stuff?or sould i use flex line befor the pump,then hard line after the pump up to the front of the car?help me sourt all this out,and let me know whats the best way to do all this?
MIKE :afro: