My heater is not working and fan is not turning on

Please use common sense in safety with the info I offer.  Do not directly(or indirectly) touch both terminals of a car battery.  
Hopefully it is not a shorted wire - this can be a real problem to trace.
If it were me, I would first check the blower motor and see if this is the trouble.  Actually, you can probably just take the motor out and attach the leads to a car battery to see if the motor spins (don't hold the contacts onto the battery for any time, - just touch them to the battery [via wire jumper cables/etc.] for a *quick* second to see if it will spin.  You could also use the output from a car battery charger to test it in this manner.  Make sure you have someone to hold it for you in a safe manner so they do not drop it when it starts to spin. 
If the blower motor is not spinning, then you can either replace it with a new one, one from a junk yard, or get adventurous.  Take the motor apart and look at the brushes - if these are worn down, do the under-$1.00-fix of replacing the motor's brushes (I took my worn brushes out of the motor - took them to the hardware store - asked to see a variety of motor brushes - found a pair almost identical in size - saved $110.00).  It is not hard to do - and generally overlooked b/c too many people are afraid to do things by themselves nowadays.
If the blower does not spin - it might be the heater is actually heating - but you cannot feel it b/c there is nothing to push the warm air out.

Another possibility is that the switch for turning the heat on may be broken. Personally, I like to tear things apart to see how they work.  So, if the blower ideas above do not work (including a new one), I would suspect this area.  I would take it apart and troubleshoot.  Maybe take whatever-the-switch-in-yours-is to a parts store and ask for help.

The blower motor for my 91 subaru legacy L won't turn, i need to change it tell me how to do it please