I was planning on listing some options for Elemental Shamans pre-Naxx, but my research wasn't going well. It is my opinion that the number one stat for Elemental Shamans (or any DPS really) is Hit Rating until you are hit capped. Unfortunately there are about zero (decent) Mail spell caster items with hit on them that you can get from Heroics or reputation vendors.
What this left me to was to just find whatever items I could with Hit rating on them. For reference, elemental shamans with Elemental Precision need 368 hit to be hit capped for Naxx. If you're a JC, there is a lovely trinket Twilight Serpent and you'll be able to pack this with two Rigid Dragon's Eye. This is a huge hit rating for one slot weighing in at 96. If you're not a JC, you won't be able to get this trinket or the gems.
If you're into PvP (or if even if you're not) the Wintersgrasp Mail Spellcaster armor has hit on it. It'll take commitment to get all the items though and there's some less than optimal stats for PvE (resiliance) but it is an option for hit items. I started down this route and ended up finding the JC stuff and stopped doing WG as I don't enjoy PvP. Your milage may vary.
There's a cloak in normal HoL (Cape of Seething Steam) that has a splatter of hit (29) on it and is easy to get (or atleast you've got more than one chance a day at it).
All your gem slots should be filled with Rigid Autumn's Glow (exalted with SoH to get the pattern) if you're still low on hit.
There are some enchants available that give hit. You should have Icewalker on your boots anyway, there's Percision to gloves, and if you're desperate there's the Titanium Weapon Chain that a BS can make and old world (BC) stuff from Sha'tar (Arcanum of Power)
And lastly, there's a food buff from Worg Tartare that gives 40 hit to bump you up that last bit during raids.
Again, I stress the hit cap for Elemental Shamans with 3/3 Elemental Percision is 368. If you have more than that it's too much and is wasted.
That's the end of the factual stuff, and now for an anecdote. Walked into Naxx on my Shaman with about 360 hit rating (couldn't push it to the full 368), 1600 SP self buffed, and 20%crit. . .walked away with 2k dps overall for a full clear. The guild master commented that I was pushing good numbers for the gear I was wearing (which I agree with, was only hoping for about 1.6-1.7k) and I fully attribute that to my hit rating. Missing takes away alot of your DPS. I also walked away with 7 pieces of gear, which is just crazy to think about.