At first you're going to want to buy a pack of heads. Then you can rebuild them when you're more comfortable with things like ohms and watts and diagnosing leaks etc. They're pretty easy and cheap to rebuild, there's a tonne of guides on Youtube. But you can just carry on buying replacement heads, they're pretty cheap.
cheers bud, not sure about the expert bit thoughI managed my first re-coil of an evod the other day, in the pub, half baked. Expert tuition from nikki from mars