Really good light - less stressful on the eyes, but also it lets you see your pattern better, and if you are working with many colours, lets you see the true colour of the bead better. I like working by a sunny window, or I have a floor lamp with a redirectable task light to put over my work too.
A steady work surface too, with some kind of mat to prevent the beads from rolling around too much. I like microfleece pads myself. Different colours so that you can have a surface where the beads can stand out from. Good posture too to prevent neck and shoulder strain.
A large supply of good sharp beading needles because that makes it easier to pick up the beads. Good thread. I have worked a lot with Nymo, but I am really digging the new Miyuki beading thread. Also a good thread conditioner to prevent fraying and to allow you to weave in and out more smoothly - I use Thread Heaven. Have tried bees wax and synthetic wax, but prefer the Thread Heaven.
If you are following a pattern, having a pattern stand or book stand helps so that you don't have to stop to flip pages or hold up the pattern to refer to it.
Also really good sharp scissors - it is a lot easier to thread the needle with conditioned thread and a fresh cut, plus good sharp small scissors to trim the stray threads after weaving.
If you are stringing a lot you may want to get a bead spinner - like this: http://www.beadfx.com/images/7509584.jpg
. Also, if you are netting, or doing a weave where you have to pick up multiples of the same colour of bead, I find that if you pile them into a small pile, and then slip your needle through the pile, chances are you are picking up several beads at once, as opposed to picking them up one by one.