I think you should just power through Hiragana first, and then Katakana. Memorize all of it. Make sure you’re grounded in their readings and pronunciation, and abandon Romanization all together (it’s a crutch now, but it’ll cause your language muscles to atrophy).

If you’re looking for a text to work from, I suggest the Genki
series. Although it’s designed for classroom use, you can mine it for the information useful for your home studies.

Considering you posted on the “Free Japanese study resources” post, though, I’m inclined to think that you are looking for the cheapest route to go. The Genki Website actually offers some free resources to work from, but they’re not really that fun.

There’s also Smart.fm to work from. One thing I suggest for hiragana is to practice writing them out so that your writing gets smooth.

After you’ve got the kana systems down square, just ease yourself into vocab learning mode through sentence digestion from any Japanese resource that fits your level. (Genki, Smart.fm lists, or whatever)

How much you learn is based on how much you invest yourself in the process. Make short-term goals for yourself, make studying Japanese a habit, and try to immerse yourself in the language as much as possible. If you are a procrastinator, you might consider joining a class at a local university or college to get a push to study, but don’t think that just attending a class will magically make you able to speak the language.

That’s all the advice I can really offer to a beginner with the limited time I’m working on at the moment. Good luck, and がんばれ！