Kava is great stuff! But most of the kava products out there are too weak and aren't worth your money. Most advise to buy the powdered root and make tea with a method such as
this one. I've read the powdered root from Vanuatu is the strongest. So far I've only used a tincture, "Gaia Herbs" brand. Get the "Professional Strength" if you want the strongest available, I looked around online and couldn't find any tincture stronger than this stuff. It has 150 mg/mL kavalactones. It says 10 drops contains about 50 mg kavalactones, if you want to really feel it try to dose about 1000 mg

I fill up a shot glass with warm water and then squirt a few full droppers of the stuff in there. I actually don't mind the taste, a lot easier to down than a lot of alcoholic beverages I've had.
The Gaia Herbs tincture: (just a product info page from the manufacturer)
http://www.gaiaherbs.com/product.php?id=160
Oh, and it goes great with weed as others have noticed. Especially useful if you're prone to anxiety and paranoia while high.
A combo I really want to try is hydrocodone+weed+kava. I think it will be just about perfect.