All programmers hate documentation, right? But I've discovered a way to make it less painful and I'm posting in case it helps anyone else.
The first trick is to start documenting as soon as you start thinking about a project - well before you've written any code. I keep a running document of the work I've done, including the bits I'm about to try, information about links into other databases or applications, issues I need to think about or questions I need to ask someone, rude comments (I know, I look like such a nice girl), references, quick use cases, bits about functions, summary notes from meetings, etc.
Mostly I record by date, blog style. Doing it by date helps me link repository files, paper notes and emails with particular bits of work, which can otherwise be tricky if it's a while since you worked on a project or if you have lots of projects on the go. It's also handy if you need to record the time spent on different projects.
I just did it like this for a while, and it was ok, but I learnt the hard way that it takes a while to sort through it if I needed to send someone else some documentation. Then I made a conscious decision to separate the random musings from the decisions and notes on the productive bits of code.
So now my document has two columns. This first column is all the bumph described above - the stuff I'd need if I wanted to retrace my steps or remind myself why I ended up doing things a certain way. The second column records key decisions or final solutions. This is your column of gold.
This way I can quickly run down the items in the second column, organise it by area instead of by date and come up with some good documentation without much effort. And if I ever want to write up the whole project, I've got a record of the whole process in the column of bumph.
You could add a third column to record outstanding tasks or questions. I tend to mark these up with colour and un-colour them when they're done. It just depends how you like to work.
It's amazingly simple, but it works. I hope it might be useful for you too. Or if you have any better suggestions (or a better title for this post), I'd love to hear them.