Hi Fribash,
I think you have the right idea for your first attempt at Lighning. I am no pro at this effects myself but used a similar technique to paint a magma effect in the past. The advice I would give it to try and neaten up a bit and make the lightning a bit more definined. By this I mean to try and paint the effect as you would do with any other part of the mini using highlights and shades.
For example, a way to make the lightning really defined is to have highlighted bright spots at the junctions of the bolts. If you use a subtle shade on the lines between these points then you have a very stylish effect. Have a look at this style of effect to see what I mean regarding the highlighted spots
http://www.games-workshop.com/gws/catalog/productDetail.jsp?prodId=prod1190053a
Your paints also look a bit thick to me. If you water your paints down and apply a few more coats you can achieve a much smoother, flatter effect. Inside the engine I can see the brush strokes where you have applied the highlight. if you had added some more thin coats over the top then the colour layer would be much more solid. There is a fine line between paint being thinned and it becoming a wash and its important to practice achieving the right dilution. Building up layers in this way is much more time consumining but the quality you can achieve makes for a very pleasing standard.
Hope this helps, keep up the good work and good luck with the Dreadfleet!!!
Cheers
Will