I was wondering if anyone could give me some advice or a starting point for creating dust being kicked up from feet whilst running?

Thanks

There isn't really a comprehensive answer to that question. It really depends on what look you are going for. It's always best to start with some sort of reference and go from there. That being said there are 2 routes you could go in Houdini - Lots and lots of particles, or volumetric smoke. Below are some tutorials from Peter Quint that cover the basics of each.

Millions of particles: http://vimeo.com/channels/54102#12092711 [vimeo.com]
Volumetric smoke: http://vimeo.com/channels/54102#9508767 [vimeo.com]

Of course you will also need to create some sort of emission system for the foot hits. There is no absolute answer for this either. Perhaps using Attribute Transfer or Jeff's geometry intersection technique would be the way to go:

Attribute transfer: http://www.sidefx.com/index.php?option=com_content&task=view&id=877&Itemid=132 [sidefx.com]

Geometry intersections: http://www.sidefx.com/index.php?option=com_content&task=view&id=1815&Itemid=216 [sidefx.com]

The fxphd HOU 101 course features dust kicked up by dragon wings hitting the ground. Perhaps your director might consider introducing a dragon 8). This is great for larger effects, but footfalls take up less screen. District 9 did dust impact from footfalls in comp.

Cinesite did dust strikes using custom microsolvers for Clash of the Titans (http://www.sidefx.com/index.php?option=com_content&task=view&id=1838&Itemid=68 [sidefx.com]), an approach which requires significantly more expertise. But it's a true volumetric effect which is also capable of handling depression of the ground so perhaps it is worth it for some frames.