I started with Heisig's book "Remembering the Kana," which is what I'd recommend completing before starting anything else. Most other resources assume that you've already learned the kana. Takes about a week or two, depending on how much time you spend on it per day. Beyond that, it's just a cycle of learning new grammar and learning new vocabulary.
Just a OT question: what have you been using to learn Japanese? I would like to learn, but obviously a new language is a huge undertaking
For grammar, right now I'm reading "Japanese: The Manga Way" (excellent book, $16 new on Amazon). Here's a great, online grammar guide to use as a free alternative, which is what I started with.
For vocabulary, I've mainly used Memrise. Start with the JLPT5 vocabulary list, which is the most basic, working your way toward JLPT1, which is the most advanced. Make sure you stick to the JLPT lists; skip over everything else, including the "Basic Japanese words" and whatever lists. Other than that, some of my vocabulary has also come from playing games and looking up the words I don't already recognize (Ni no Kuni has been great for this).
Optionally, you can pick up "Remembering the Kanji" by Heisig (same guy who wrote "Remembering the Kana"). If you want to be able to write Japanese, definitely pick up a copy, but if you only care about being able to read Japanese, it's optional. It's an old book, so you can get it for cheap; I snagged a used copy for $5 on eBay.
I'm also working on a web app of my own for learning Japanese right now. Doing it in my little free time means its launch is still months away, but I do believe it will be more useful/effective than anything else that's available right now.. the approach I'm taking with it is very unique.