Since you are already working with HTML/CSS I would definitely start with Javascript, like others have said.
From there, I would start by looking at what your goals are first. Why do you want to learn? Do you want to build something for yourself, or others? Is it just for fun or do you eventually want to get a programming job.
For example if you want a good job in my hometown, you end up working in Government. So if someone were to ask me what the best language is for them to get a job, I'd say look at the .NET framework (which is what the majority of our Government uses).
Personally if I just had to throw out a language, I'd say Ruby.
Being the only hacker I can understand you are working very hard to get the project off the ground. Keep in mind that eventually as or project come closer to launch, you may find you require level of effort go down, and their go up quite a bit.
I need help in this category. I'm currently doing consultant work full time to pay the bills (and keep the girlfriend happy) while working on my startup nights and weekends.
My girlfriend simply HATES computers and this makes it hard for her to understand what I am doing, why I am doing it and what it could mean later on. To her, it's not work, since it's currently not bringing any money.
Luckily she does let me spend some time on my startup, even though I could be spending it her. Going to take advantage of it while I can.