The "just do it!" advice never works for me, personally. If it was that easy for everyone, no one would ever ask how to be more productive.
Eat That Frog is one I found pretty helpful. Getting Things Done by David Allen is also well worth reading. He shows you how to build a system for being productive. Again, not focused on writing specifically but the principles can be applied.
There are a couple of blogs I'd like to point out, too.
Asian Efficiency, which is a variation on Getting Things Done and also focuses a lot on routines and maximizing productivity. With the added bonus of being free, of course.
And also
Lifehacker, which isn't about productivity per se, but does have a lot of related and useful content.
Right now I'm kind of using a combination of things I've picked up from the above. I'm not successful all the time in maximizing every minute of every day, but I am getting a whole lot more done than I used to, and faster too.
I'll use an example of something I do right now that makes life a lot easier. I have a giant notebook that every day I turn to a new page, write the date and divide the page in half. On the left side is my actual running to do list. There are usually 15-20 things on it, everything from doing taxes to household chores. On the right side are my project notes, that is, information I need to get a multi-step project done. For example, making a list of all the paperwork I needed to have handy when I did my taxes. Or writing down the vet's phone number for when I need to call in a refill on my cat's medications. As I complete things, I cross them off the list. And I simply transfer anything I didn't do to the next day's list, then add whatever needs to be added.
Yes, I could do it all on a computer. I tried, it didn't work. Spent all my time trying to make the perfect system on the computer, as opposed to just scribbling things down in a notebook. Plus having it down on paper and out on my desk means I actually look at it.
The one thing that I don't really do and probably should is make an actual schedule. Having a to-do list is all well and good, but without a set routine I admit I often fall back into old habits, especially when I'm tired or stressed out. Which unfortunately is a lot these days. But anyway, being productive isn't just about making time to do one thing, it's keeping up with everything you have to do so you can set aside the time for what you want to do.
