Step 0 - Get a spare set of rims and the hardest tires you can find in the stock width. If your car didn't come with a factory LSD, swap one in. Now. Get coilovers if your suspension needs work; you'll need them in the long run.
Step 1 - Find a safe place to practice. Safe means safe from obstacles, traffic, and the law. Usually, this means a skidpad at a track, or an empty parking lot. Loading docks at a warehouse can work, too.
Step 2 - Get sideways there a couple times per week. Practice makes you comfortable with what's going on with the vehicle, and introduces you to its quirks. Learn to deal with them.
Step 3 - Research. Watch the Drift Bible a couple times, read through some drift forums and a few books on general performance driving. Chances are, there's a drift forum specific for your area; meet up with drifters in the area, talk cars, technique, etc...learn everything you can while still practicing.
Step 4 - Practice some more. You should be getting a feel for what needs to improve by now.
Step 5 - Get some track time; skidpad sessions work wonders for confidence, because people will be watching. Talk to whoever you can afterwards, see if anyone has suggestions. If possible, do an open drift event, and get some live instruction.
Step 6 - Practice even more. Learn how to compensate for certain characteristics of the car; the mk3 is heavy, which means drifting with weight transfer is going to be easier than drifting on pure power.
(notice a pattern here? good. keep practicing.)
Then start upgrading. Chances are, you'll find a need for more chassis/suspension parts, and a little more power. Stock N/A mk3s can break loose, you've just got to learn how.
