If there is no clicking when you turn the key your neutral safety switch might be broken. It is on the steering collum on the bottom near the middle, looks like a cresent shaped electrical box with a couple wires connecting. Basically kills the ignition in case you try to start your car in gear so it doesn't jump.
few things to try ,1) starter or starter solenoid , 2)hot wire going from battery to starter grounding out againt exhaust manifold , 3) Ignition and of course the the neutral safety switch,if it turns check out your points,coil and for spark or fuel pump,since you didn't leave any detail on what is going on "just don't start"
my nuetral safety switch is mess up so i jus hold the shiftr up wen i try to crank it easy way to decide if thats the problem u can always pull off a the cap to see if distributer if getting spark also...if u have points just save ur self the trouble and convert.
did you try jumping it at the starter . with a screwdriver? you have to have the ignition on . then do it. do you know what i mean? ...if it cranks over then it might be your wire from the starter to the firewall and it runs along the fire wall over towards the steering column...kinda looks like a braided wire...probably the issue...check it out. mine was loose one time not making a good connection....just trying to kick in some more help homeboy...