http://www.garretwilson.com/education/languages/hindi/devanagari/
This site is truly the Idiot's guide to devanagari, complete with stupid mnemonics, enthusiastic encouragement and reassurances, and tiny bite-sized steps. On the one hand, my arrogance is utterly offended by the incredible simplicity of it. On the other hand, I've worked my way through almost all of it, and at this point am slowly and laboriously reading a majority of the printed Hindi words I come across without reference to a chart, including being able to accurately interpret conjucts even when I haven't seen them before. And, I'll admit this here, I did a lot of it while bored in class, which means my concentration, never all that good, was even worse than usual.
This thing is the opposite of intensive, and if cute mortally offends you, you'll hate it. But even though it's not my preferred style at all, it's really working for me, which makes me think it would quite likely work for a lot of different people.
It's very definitely a reading guide, not a writing guide. It doesn't teach stroke order, or how to create conjuncts, or things like that. So far, the recommendation I got here for this Hindi script tutor is the best I've encountered for that. But for character recognition and retention, this stupid site is actually really good.