Yes, a good camera and accssories are somewhat important, BUT, it's my belief that you can take a pretty decent picture without anything more than a $250 3MP camera and no accessories. Sound impossible?
The things that I feel are way more important are:
Your patience. I will often take literally 50-100 pictures of the same knife, go through them carefully, edit them in my 5 year old, primitive photo program (yes, i should get Photoshop) and pick the 3 or 4 I think are good. If you think pro photographers take one or 2 shots of their subject, you're wrong.
Next, LIGHT!!! It's been said before, it bears repeating. Lighting is nearly everything if you want a really good picture. Its the only way to have the entire knife lit evenly, without bright spots, reflections, etc. And, outdoor, natural light is by far the best IMO. Not direct sunlight, just ambient light. I am now in the habit of going to Starbucks, where I go anyway for my daily caffiene fix, I take knives with me, background paper, camera, sit outside on their patio tables, and at my leisure, drinking coffee take usually about 100 or so pics. I acually find it relaxing. Yes, I believe I have seen a few people staring at me oddly, screw them.
Thirdly, you do need to develope a good eye for balance and angles in your pictures, that can be helped by taking lots and lots of pics from all sorts of angles, but you still need to learn to take a nicely balanced picture and that comes with a little practice. I'm not a pro by any stretch, and use low-end equipment, but I feel my pictures, especially lately, are pretty decent.
I admit that now, i want to get a better camera and get that last little edge, but again, that is the least important thing.
Here are some pics I took recently, remember, $250 3MP Sony camera my wife actually got for free, and no tripod, no photoshop, nothing really, except light, and a willingness to stick with it until I think it's right.