As I mentioned in other areas of the Dojo, the translator's main dictionaries are the Green Goddess (Kenkyusha's New Japanese-English Dictionaries), Nelson's (Japanese-English Character Dictionary published by Tuttle), The Wordtank electronic dictionary by Canon, and some on-line sources.

Here are some of the ones that I don't use quite so often, but can save your neck at times. Note that most of these were bought quite a long while ago. There may be new editions or some might have gone out of print. The ISBNs are the ones on the back of my books. I wish you the best of luck finding them.

Sanseido puts out a set of four Japanese-Japanese dictionaries that can be immensely helpful at times.

Concise Nihon Jinmei Jiten (The Concise Japanese Names Dictionary) which lists historical Japanese names.
ISBN 4-385-15804-5

Concise Nihon Chimei Jiten (The Concise Japanese Place Names Dictionary) which lists all sorts of places in Japan.
ISBN 4-385-15328-0

Concise Gaikoku Jinmei Jiten (The Concise Foreign Names Dictionary) which lists the katakana spellings (kanji for the Chinese people) and a short bio of famous people throughout the world.
ISBN 4-385-15325-6

Concise Gaikoku Chimei Jiten (The Concise Foreign Places Dictionary) which lists the katakana spellings (kanji for China) for countries, towns, rivers, etc.
ISBN 4-385-15335-3

Then there are:
Concise Katakana-go Jiten (Concise Katakana Dictionary) is a Japanese-Japanese dictionary for katakana words, but since the Wordtank just about replaces this, I hardly use it anymore.
ISBN 4-385-13477-4

You need a good standard Japanese-Japanese dictionary because they contain words that the Japanese-English dictionaries don't have. I have Sanseido's Shinmeikai Kokugo Jiten (New Lucid Japanese Dictionary)
ISBN 4-385-13069-5

It doesn't hurt to have a kana-based Japanese-English dictionary. I still own the one I picked up during my college days. Kenkyusha's New Collegiate Japanese-English Dictionary.
ISBN 4-7674-2056-3

The companion English-Japanese dictionary is the only E-J dictionary you will ever need (once you get good enough with kanji to read the entries). Kenkyusha's New Collegiate English-Japanese Dictionary.
ISBN 4-7674-1076-2

This is one I hardly use since Nelson's is so much better, but when I can't figure out how to look up the first kanji in a compound, this one gives you the option of looking up the second or third kanji in the compound. So in that particular case, it's a great fall-back dictionary. Japanese Character Dictionary by Nichigai Associates.
ISBN 4-8169-0828-5

This dictionary is a pain to look anything up in, but it helps when getting into technical names for commonly used items since it also has pictures for every item and they're grouped by specialty (Farming equipment on one page, shipping on another, etc.) The Oxford-Duden Pictorial Japanese-English Dictionary.
ISBN 0-19-864327-6

Since there is no help for Japanese names -- even native Japanese speakers can't be 100% sure of the pronunciation of a name written in kanji -- this dictionary is almost useless. But I did say almost. If you have no choice, and you need the pronunciation of a name, this is the only one that has a chance of giving it to you. Japanese Names by P.G. O'Neill published by Weatherhill.
ISBN 0-8348-0225-2

There's a slightly out-of-date dictionary of Japanese manga creator's names with short bios that's helped me any number of times. Mine was published in 1997. I'll have to see if there is an updated release. Mangaka Anime Sakka Jinmei Jiten (Dictionary of the Names of Manga and Anime Creators).
ISBN 4-8169-1423-4

I was lurking on a forum when I heard about this sound effects dictionary. It's Japanese-Japanese, but it can be very helpful when that weird sound effect that you haven't learned yet comes up. Gendai Giongo Gitaigo Yôhô Jiten (Modern Sound Effects and Onomatopoeia Usage Dictionary)
ISBN 4-490-10610-6

Shogakukan puts out (past tense, maybe?) a dictionary of movie, song, and other media titles. This includes the Japanese titles of foreign movies which are often quite different from literal translations or transliterations of the original titles. Like most media-oriented dictionaries, it's only good up to its publishing date (1997 for mine), but it has often helped when a shôjo author starts talking about that foreign movie that so inspired her. Eeiwa Waei Title Jôhô Jiten (English Title: Shogakukan Companion to Artistic Works).
ISBN 4-09-510192-X

Oh! And be sure to get Kodansha's bilingual maps of Tokyo, Osaka, and all of Japan. They've saved my butt plenty of times.

Of course they aren't all of my dictionaries. I have some completely useless ones (a small medical dictionary hasn't given me one word that wasn't better documented in the Green Goddess in the 10+ years of hopefully looking things up) and others that have been replaced by better dictionaries above. But you have to be something of a dictionary junkie to be in this business.

If you know some useful dictionaries that I haven't mentioned, get onto the Contact Sensei page and let me know about them! Now, dammit!