I just got a Mustang from my wife's Grandfather who just passed away. The Vin # is 5F07U103685. I believe it to be a 64 1/2. He bought it brand new and drove it for a few years then parked it in his garage, never to be driven again. He had it on blocks all this time.
The car seem to be in excellent shape from what I know of cars. I even have all the original paper work that he got when he bought it, bill of sale and all. He only paided $2,544.00 for it brand new in May of 1964. Where do I start on restoring this beauty?
Thanks  

Start by getting some good books, read up a little, it will serve you well. Get a mustang monthly subscription, watch the forum here and get catalogs from NPD, CJPony, Mustangs Plus and a Jegs or Summit will help too. Just perusing the catalogs will give you a price and a place to start. You will see whats available for your pony. Then go to a few local Mustang shows and see other peoples cars.  

Ditto above, as its sat more than its worked, you have the road in front of you, take it slow, do your research, & make sure you want to do it, if not then sell to an enthusiast, but you have a great family reason to give it a go.
A good book is:"Mustang 641/2-73" by David Newhardt  

If it has been in a garage all these 40 some odd years, most likely you are not facing much rust damage to the body.  Normally,that is where most guys start in a restoration project.  The seats, carpet etc, on the interior may be rotted out and need replacing.  Now, the last thing is the running gear.  Most likely that engine is frozen up.  I would try to see if the engine turns over.  You do that with a socket and breaker bar on the nut in the middle of the fan.  Pull out all the spark plugs and squirt some penetrating oil in the cylinders, then try to turn over the engine.  If it won't budge, it is frozen and the engine will have to be torn down and refurbished.  All of the fluids will obviously have to be changed such as the transmission and rear end and brake fluid.   Here is a library of information you may want to peruse to pick and choose what in here you need for information in your quest to bring that baby back to life.  This site does not allow you to click on this URL, but I can gurantee you and anybody else it is well worth the time to write it down use it. I spent several years compiling all this information off the internet.  

http://www.mustangv8.com/forum/classic-mustang-technical-forum/classic-mustang-faq/  

So ,today I filled the front tires up with air bought and installed a new battery, put gas in it, checked the fluid levels and, believe it or not it cranked right up and I drove it on to the car trailer. I just knew it was going to take me forever to get it on there. Today I also found the original owners manual in the truck with the spare tire. It only has 66,000 miles on it. No rust and no cracks in the inside. even the head liner is intact. I can not wait to get started. Just thought I would share this.  

So ,today I filled the front tires up with air bought and installed a new battery, put gas in it, checked the fluid levels and, believe it or not it cranked right up and I drove it on to the car trailer. I just knew it was going to take me forever to get it on there. Today I also found the original owners manual in the trunk with the spare tire. It only has 66,000 miles on it. No rust and no cracks in the inside. even the head liner is intact. I can not wait to get started. Just thought I would share this.  

You might want to erase the double post.  Anyway, wow!  That is amazing.  You can consider that mustang a survivor.  Take it easy on driving it around for awhile. Be sure you grease the upper and lower ball joints as well as the U-joints.  Change out those fluids as I suggested, and use synthetic oils.  

Make sure anything you take off it is not an original part before you toss it. If you dont want it there are people out there looking for original parts for their car.  Stuff like Battries, spark plugs, spark plug wires, stuff like that that may seem like junk could be worth a pretty penny to someone.Just an FYI. Only reason I mention it is you said it was only driven for a few years and you never know.  

Maybe you don't want to restore it.  They are only original once.  See if you can clean it up, fix everything that's wrong with it and enjoy it.  

This is a late post (just discovered the website), nevertheless you are very fortunate to have an original car without modifications.  Please contact (or join) your local chapter of the Antique Automobile Club of America (AACA).  Only restore what is defective and do it with "original" parts.  If you want to restore a Mustang, buy a Junkyard dog and make it new, like I did.  Have fun with your new toy!!  

One word, brakes. Flush, rehone or replace wheel cylinders where needed. The brake hoses are old,old,old. Replace.

cushman  

I'm with Cushman on this this, replace anything that's rubber or flexible. especially brake and fluid hoses.