1) Acquiring the correct thermal paste. There are many available thermal paste in Computer stores under $10 but it is important that you acquire the most efficient thermal paste available. The basic thermal paste compound contain zinc oxide and silicone. This costs under $10. More expensive compounds contain a better heat conductors such as silver or ceramic. Although the basic thermal paste would be enough to do the job.
2) Cleaning materials such as cotton swabs/balls damped with Isopropyl Alcohol. 70% solution is enough but the higher the percentage the better.
3) Other important materials like phillips/flat head screwdriver for opening up your laptop. Anti-static cleaning wipes is also particularly useful.
4) Plastic card for spreading the thermal paste.