Posted: 18/04/2013 at 12:56
There's a website calendar here - http://www.the-gardeners-calendar.co.uk/Moon_Planting.asp It doesn't give a complete list of doable tasks so you have to read the info about what to do on root/flower/leaf/fruit/maintenance days. You can use the simple lunar phase guide, the biodynamic guide or the sidereal depending on how complicated you want to be. I tend to go with biodynamic.
I find it very helpful for organising my time as I tend to stick to the tasks I've set out to do instead of letting myself get distracted by jobs/weeds/pruning that I see out of the corner of my eye. Even for those who are sceptical about the moon's ability to influence plants, it's a good organisational aid.
As for your spuds being late, I'd say not. Better to plant them when teh soil is warmer than risk giving them a chill and setting their growth back.