Some basic reading for understanding relays in general and how to use them:
http://www.bcae1.com/relays.htm
Go to your favorite auto parts store or buy from the web one 30 amp relay with associated mount and wire leads such as these:
http://www.ebay.com/itm/30-40-AMP-R...007?pt=LH_DefaultDomain_0&hash=item3f2348b47f
http://www.ebay.com/itm/5-PACK-30-4...H_DefaultDomain_0&hash=item5ae94a4c52&vxp=mtr
This type of relay will need to be mounted in a protected place such as the spare tire compartment which is near the starter area and will require fairly shot leads. They do make weatherproof relays as well if you decide to mount it in the engine compartment.
You should also buy an inline fuse holder to protect the car should anything short out.
Some 10ga wire, some 16ga wire and associated crimp on connectors, both male and female spade type.
Hookup is as follows:
1. 5/16" eyelet and 10 ga wire from starter battery cable terminal to #30 terminal on relay.
This is where the big thick wire goes on the starter. You will be running from this to the power side of your relay which is terminal 30. Get out your bifocals to see the little numbers on there... You should include an inline fuse on this just to be safe.
2. 10ga wire from 87 terminal on relay to solenoid spade terminal on starter
This is where the wire from the ignition switch went. Your new wire goes from the relay to this terminal.
3. original spade terminal wire to terminal 86 on relay
This is the wire from your ignition switch with a jumper you will make to go from the original wire to the relay. This wire does not need to be heavy gauge as it just takes a few microamps to turn the relay on and off.
4. wire from chassis ground to terminal 85 on relay.
This is also a light gauge wire and just needs to go to a reliable ground in the engine compartment. You might find a ground bloom near the coil or ground the to same stud the coil does.
Also is the relay just a generic relay that I can purchase at my local auto parts store or does it need to be of a certain size or type?
You can use either generic form of relay, DPST or STST, the powered output will be what goes to the starter solenoid. If you use a DPST you will connect the starter to 87 with no wires connected to 87a. Buy a 30amp relay.