This question is related to the questions (here) and (here) regarding a word or verb with multiple kanji options, for example [作る、造る、創る] or [蔵、倉、庫]
Is there a resource somewhere that will tell me the nuance differences in between the kanji? This can be in English or in Japanese. Teachers will often give me a distinction, but I haven't found a way to look this up myself.
There is an official document (「異字同訓の漢字の使い分け例」) that covers a number of these. For example:
つくる ０８４
【作る】こしらえる。米を作る。規則を作る。新記録を作る。計画を作る。詩を作る。笑顔を作る。
会社を作る。機会を作る。組織を作る。
【造る】大きなものをこしらえる。醸造する。
船を造る。庭園を造る。宅地を造る。道路を造る。数寄屋造りの家。酒を造る。
【創る*】独創性のあるものを生み出す。
新しい文化を創（作）る。画期的な商品を創（作）り出す。
* 一般的には「創る」の代わりに「作る」と表記しても差し支えないが，事柄の「独創性」を 明確に示したい場合には，「創る」を用いる。
Or this, which is admittedly a little less helpful.
くら
倉－倉敷料。倉荷証券。
蔵－蔵屋敷。蔵払い。
See links from the Wikipedia article or online version
While ssb’s answer is absolutely sufficient, I want to point out—in addition—an English resource that some may not think of in these circumstances.
Of the three current, major kanji–English dictionaries (Nelson, Spahn–Hadamitzky and Halpern), Jack Halpern’s New Japanese–English Character Dictionary is actually rather well equipped with information suited for us beginners.
This is part of page 47 (and a small inset of page 46), covering about a fifth of the total entry for the kanji 作:
While the other kanji dictionaries in English cover more kanji and use a (slightly) more traditional radical look-up method, they come nowhere near the amount of semantic information Halpern covers in this dictionary. They each have their own strengths and weaknesses, and I would like to say that this is Halpern’s strength.
(The latest edition of this dictionary goes under the name The Kodansha Kanji Dictionary. And it seems to have been expanded by some 1,000 kanji entries, 5,000 senses and 7,000 compunds; as well as some further 1.000 synonym expositions and about 100 additional usage notes.)
One low-budget option is the IME. Microsoft's IME (and possibly others) has little comments next to the homonym kanji that help you to choose the correct one:
