This, obviously.
The Genki books go over all the basic grammar as far as I remember and teach a few hundred kanji at the same time. This is good for a start. At the back of the book you'll find tables of all the kanji mentioned in the book, as well as related vocabulary so you can expand your knowledge further, it helps to go over those nice and slow. The trick to learning kanji is that you'll use the earlier ones you've learned to learn new ones connected to them, so for instance you'll learn that 食べる is "to eat" and later you might learn more complex stuff that uses the same kanji, like 食事 (shokuji - meal) or 食欲 (shokuyoku - appetite) and so on. As you can see they all sort of originate from the 食 kanji, in a way. Oh and for the moment don't worry about learning the different readings of each kanji individually (onyomi and kunyomi, each kanji has a Japanese and Chinese reading), at least at your level. It will sort of come naturally as you learn more and more kanji.
Also to add to that, one useful feature of Jisho is this:
http://jisho.org/kanji/radicals/ Basically it allows you to look up kanji based on their radicals, aka the building blocks they're made up of.
It also helps if you expose yourself to as much language as possible, so for instance watching anime and jotting down new vocabulary.
Ah, one more thing. This site:
http://www.guidetojapanese.org/learn/grammar It's a very complete and thorough grammar guide, it might be a bit too overwhelming and honestly for now I'd just stick to Genki, but it's good to know about it. In case you ever need some extra help.
Originally Posted by Gare
This, obviously.
