Need a whetstone, or an oil stone.

Look at a restaurant supply, or wholesale grocer like cash & carry , should be able to get a stone for around $20.

There are tons of thread in the archives about this (trust me, I've spent a ton of time reading 'em).  If you're talking about Euro carbon steel or average stainless, I don't think you could get any better bang for the buck than a Norton IB8 (about $20 bucks, coarse on one side, fine on the other).  It supposedly doesn't work well on high end stainless or Japanese carbon steel (they're too hard) though.

I'm happy with mine.  Amazon carries this stone as well as any reputable knife shop.

Just look for posts by "boar_d_laze".

Doug

Hi Onepiece,

I'm pretty new around here, but that has the advantage of my having been a recent comparison shopper at the low end.

I don't know where you live, but in New York Chinatown you can find stuff like this:

(dollar bill for scale)

...for all of $5.50.  There is a MUCH larger, and to my eye higher quality one, for $20.  When I say big I mean something like 16 inches long x 2.75 inches wide x 2 inches thick.

If I had to spend $40 at max I would buy one of these ~$5 stones and then something like this:

http://www.amazon.com/King-Combination-Waterstone-1000-6000/dp/B0037MCLLO/ref=pd_sbs_t_11

The cheap stone will do the repairs and such quickly and the 1000/6000 will take the knife to a very, very fine edge.  If you do not need as good an edge as that, maybe something like this:

http://www.amazon.com/King-Bear-4000-Grit-Waterstone/dp/B0037M6VBA/ref=pd_sbs_t_13

...will be be a better value in combination with the cheap stone -- most of the time, you get less stone (sheer volume-wise) with combo stones, and the King 1000 does wear down relatively fast, so make sure you look at the measurements before you buy.

Good luck and enjoy your sharpening.