If you knit socks, you will most likely be using thin needles.
I knit loose and I prefer thin socks. This means I use exclusively 2mm needles. In fact I am now starting to consider 1.75mm needles.
I knit Magic-Loop style, 2 socks at once (either top-down or toe-up). So I need a circular needle that is a good 47" (120cm) in length. For the odd repair, I need a set of DPNs (and I prefer sets of 5, so the sock is divided into quarters and I knit with the 5th needle).
The best source for knitting needles I've found is KnitPicks. This is an online store with a large selection of yarn and equipment. They sell nice needle sets down to 2mm. The circular needles are smooth and the cables flexible and kink-free. I've tried Inox brand needles but I hate 'em (the cables are stiff and the needle-to-cable join snaggy), and Addi's are too expensive for my budget.
However, KnitPicks does not sell anything less than 2mm. So the only other place I've found is HiyaHiya, which sells circular needles down to 1.5mm. I've got a set of 1.5's and 1.75's, both 47" in length. They are not quite as nice as the KnitPicks (finish isn't so nice and the cable is clear, which somehow I don't like as much), but the price is good. HiyaHiya also sells very small diameter (down to 0.7mm!!) DPNs.
To tell apart these needles you must have a needle gauge. Finding one that goes below 2mm is just as hard as finding the needles, so HiyaHiya is the place to go.
I don't have a good circular needle storage solution. I've put an accordion-style one on my seasonal wish list...although for a more personal touch, I'd prefer a handmade one from somewhere on http://www.etsy.com/.
For storing my DPNs, I use a slotted tube. I've got a paper one that doubles as a holder for "work in progress" (ie. WIP tube), and a wooden one that is much nicer, but quite a bit bulkier.
Oh, and I recently discovered that my nickel-plated needles were all dull and matte and yucky-feeling after a summer's break. I gave them a quick rub with my silver polish cloth and they are back to normal!
One last thing about small-gauge needles: they deform easily. The heat of your hands the stress of knitting will bend them quite quickly. This does not affect the knitting (you might even consider the needles ergonomically shaped to your hands!) and in any case slight bends are easily fixed by bending them back. A hard bend is very difficult to fix.