I started training for the channel in earnest in January '07. To be honest, I really didn't know how to prepare for something like this, and everyone seems to prepare differently, I did what I think was right based on various bits of advice.
What I learned along the way was that training until the open water season should be all about speed, there is plenty of time to build up stamina once Dover starts. The reality was that in this year I also needed to build stamina as we had our qualifying swim in Gozo before the open water season started and I was concerned that I wouldn't be able to manage the 6 hours otherwise.
Next time, it will be speed work only until May.
Once I started moving the focus to open water, the focus has shifted from metres to hours. The table below shows how quickly the time spent in the water has increased in Dover: