You just have to go out and do it. It's actually really, really easy.
You can learn to read them (slowly) after spending a couple days with a flashcard program and no previous experience. Just use any kana flashcard website. It doesn't have to be too mind-numbing, either. While you're doing something else more important that doesn't absorb all of your attention, start hitting the flashcards while you're doing it. When it shows you one you don't know (all of them at first!) you just get them wrong, and then try to remember it for next time. You can read them, slowly
, after a weekend of this. If you're so inclined, you could use the demo for http://lrnj.com/
as well, but.. you should probably stop before the kanji
It's not necessarily the best method for learning them.
To make sure you understand all the correct sounds, (of course you have japanesepod101 to help with that), I used the http://www.humanjapanese.com/home.html
demo. It starts with romaji, but quickly moves on to hiragana, and every symbol displayed throughout the life of the program can be clicked on to produce a sound example. It also shows you the stroke order for all the hiragana characters along with tips on how to make them look neat, so you can go through it and learn to write them, which will also speed up your recognition. It also has really basic sentence stuff and some entertaining cultural notes.
Then you can use whatever else to continue learning to writing the hiragana and start writing the katakana, including a purchase of Human Japanese if you please. Those PDFs above are also an example. Then the exposure of reading the hiragana Jpod101 pdfs every day will help, and go ahead and practice writing out all the sentences in there as well. Or whatever else you do. Give it a couple weeks and it'll all be second nature.
The kanji is where things get difficult. I recommend the Heisig method. A lot of people find it unorthodox, but there's a sample PDF that takes you through the first 267 kanji at http://www.nanzan-u.ac.jp/SHUBUNKEN/pub ... sample.pdf
so that you can get a feel for it.
You DON'T learn how to read them using this method, but you learn how to easily recognize and write all of the jouyou kanji. I've been doing it for a few months and I can write and recognize 1700 kanji, though, again, I can read less (I couldn't put a number on it) as I use a 'learn the readings in context' approach, through reading manga and etc. I've personally found it invaluable, and find it incredibly easy to learn new words, including their kanji, now that I'm intimately familiar with their writings. If you were to use this method, I would recommend http://kanji.koohii.com/
as an excellent (free) supplement. It has a built in Spaced Repetition system, as well as a database of user-submitted stories/mnemonics, which really make the whole thing possible.
I don't have any recommendations for more traditional kanji methods, as the couple of months I spent trying to use them were very painful and gave me extremely poor results. But, they're out there and ready to be found!
Whatever you do, it is really invaluable to learn how to WRITE the characters, and not just recognize them. When it comes to different, TINY fonts, such as those found in wordy manga and videogames (not to mention the handwriting of most mangaka), they're virtually impossible to reason out with only recognition experience. On the other hand, when you know how to write them, you can recognize them in most any computer font, no matter how mutilated they become. And oh, they become ever so mutilated