Lighting and heating the greenhouse

I have a wooden 6 x 8 greenhouse on one of my plots and want to try to extend the growing season.

Over winter I have had some broadbeans and peas growing with a reasonable amount of success.  They are now finished and I would like to try to get some early veg growing to mature before the tomatos and cucumbers are ready to plant out.

Has anyone used artifical lighting to any success in a southern counties greenhouse?  Do you need specialist bulbs and how long should they be on for each day? What sort of temperatures are needed and can this be acheived with a standard parafin heater.

As usual any assistance would be greatly appreciated.

I am stuck in bed again, just like this time last year with another DVT!  At least this time they know what has caused it and hopefully we can sort the problems out without too much difficulty.

Regards

Rugbymad40