For years I've had an on and off routine with meditation. One of the issues I've always had is the whole issue around the breath.

Alan Watts during the recording about Meditation in Exercise 1 - Lesson 3, talks about (or rather demonstrates) extended breathing. I've never been able to extend my breath without having to be overly focused on it. It seems as soon as I put any focus at all on doing anything else with my breath than its doing naturally (which is always more shallow breaths), I lose focus on my state of mind and soon become frustrated.

Is this normal? Does one need to have extended breathing at all in order to properly meditate? And if so (or if it certainly does improve meditation), how can I achieve extending my breathing during meditation without breaking my meditative state of mind?

In my experience, extended breathing does aid meditation in that it slows many metabolic processes but from a strictly mental standpoint its not an absolute necessity. That being said, I find that, at least in my early stages of meditation, focus on the breath is helpful. It takes me out of my own thoughts on the future or the past or even on what I'm "trying to do" and instead I'm just breathing. Once I've focused on breathing long enough I can become aware of my thoughts regarding the breathing and then begin to direct my thoughts where I would prefer them to go in my meditation.

In light of that, I generally don't try and focus my mind in meditation except when devoting time to direct my thoughts toward someone or an event. My meditation is more focused on simply experiencing the present moment and through it the Force. My thoughts aren't focused on the Force however as that can just as easily lead to focusing on the mental contruct we have of the Force rather than the Force itself.

I completely agree with what Lila had to say. The NOW is all there is...

The Force will be with you, always.