TOU, this, the said, that a(taru/teru) to hit, prove correct, be assigned, correspond to; make (something) hit (something), call on, expose, succeed
- what's the point in that? It won't help you to read words. It won't help with writing. If you have flashcards that use this format, burn them. (Or, okay, recycle them).
Don't be obsessed with having to know all the 常用漢字, either - they're about to change the list anyway. To read, you need to learn words, in context (and the grammar that surrounds them) - e.g., for '当' you could have:
弁当 (公園でお弁当を食べませんか)
本当 (彼の話は本当だった)
当たる (この部屋は良く日が当たる)
Then, you should be testing yourself kanji --> kana and kana --> kanji
公園でお
弁当を食べませんか (answer: べんとう)
彼の話は
ほんとうだった (answer: 本当)
(add furigana over the other kanji words that you're not testing yourself on if you need to. English translation of the sentence to only be used if you really need it.)
This is the main way kanji is tested on the Kanji Kentei. Particularly for words like あつい where you must understand the context to know whether it's 厚,熱,暑 (or even 篤).
Examples, testing the ability to produce the correct kanji, might be something like:
1. その氷はとても
あつい
2. 日本では夏は
あつい
3. このお茶はとても
あつい
Basically: vocab, vocab, vocab. grammar, grammar, grammar. The more you pick up, the more you'll start to recognise. You might enjoy something like iKnow - and there's also an JLPT based kanji-reading site (just covering JLPT vocab) called Read the Kanji Both have the advantage that they keep track of your progress for you, which can help with motivation.
I also use component breakdown to some extent - having learnt 夜, it's easy to write 液 (and the radical on the left hints at the meaning). Sometimes the right-hand side of a kanji is a clue to the on-yomi - i.e. 同 can be read 'dou'. So can 銅. Kanji with 長 as the right-hand radical often have the on-yomi "chou".
Try and do a bit every day - and if it starts feeling like a grind, stop and do something more interesting. Type 無料ゲーム into google, look at the Japanese wikipedia article on your favourite subject, try to follow a recipe in Japanese. I like 謎々 (riddles).