Potentiometers (250k if you have single coil pickups, 500k if you have Humbucker pickups). As for the brand, I would recommend CTS for they're quality.
Switch. Since there are many different models of guitars, do research to find out the right one for your guitar.
Pickups. You can either reuse the old ones or buy new ones.
Jack. I would recommend the 1/4 inch switchcraft #11 mono input jack.
Wire. I would recommend cloth covered guitar wire.
Capacitor. You need this fore the tone control of your guitar. Sprague orange drops are the best bang for your buck. Common values are .022uf for humbucker pickups and .047uf for single coil pickups
I've found that ebay has the cheapest prices for all these parts.
60/40 ROSIN CORE SOLDER. DO NOT USE ACID CORE SOLDER!
Phillips head screwdriver
Helping hands. (Soldering tool which has two alligator clips and a magnifying glass) It's a must have.
Wiring diagram specific for your guitar
Step 2: Disassembly
Note, You may have to cut the jack wire to get it out. If so, try to cut it as close to one end as possible so if your reusing the wire you will have enough slack.
Step 3: Preparation
Now is a good time to plug in your soldering iron
Step 4: Soldering
The first thing I did was solder all the colored pickup wires to their correct positions on the switch. You can solder the components on in any order you want. Make sure that all the wires go to their correct places. A lot of times the jack wire goes through a small hole in the body, so make sure that the jack is mounted in its correct place before soldering it into the circuit.
Step 5: Review
Step 6: Finished!
I hope this instructable was useful and helped you fix or upgrade your guitar.