I was in the same position as you around 18 months ago - the best advice I got was to practice.
Get an A3 sketchpad and doodle away, test the pressure settings and the feel of the trigger and try to shade and fine line until it all becomes natural.
Paint thinning is down to the manufacturer but 50/50 is usually a good start - skimmed milk consistency seems to be the rule, but if you want to do it the easy way, the "Vallejo Air" range are perfect to spray straight from the bottle

Keep your nozzle clean as you go to avoid spitting and always clean completely after use. The tank setup you have will give you a nice airflow without any pulsing, I found it a huge improvement over the "no tank" setup.

When you have been through the sketchpad, try some plastic - buy a pack of spoons and try some gloss spraying.

Then, get a cheap 1/24 car kit and try to build and spray it as clean as you can with a perfect finish Good luck, you'll be a natural in a couple of weeks.

Steve

Wish you well with your airbrush setup.

If i could just give one word of advice it would be to get yourself a good face mask because any paint if inhaled can prove a hazard.

Happy New Year to you and enjoy your builds in the coming year

Pretty good advice there by everyone.

I would add that when the weather starts getting warmer and humid that the addition of a paint retarder can help immensely to stop the painting drying too quickly when it comes out the airbrush. I use Liquitex (http://www.amazon.co.uk/Liquitex-Professional-Flow-Effects-Medium/dp/B000KNPM46) it will last ages as you only need 1 drop per paint cup of paint.

Learning how to strip down and clean the airbrush properly is vital as a brush that is not cleaned well can cause you issues with spitting and clogging. Watch a few videos on cleaning airbrishes. I can recommend the ultimate airbrish cleaner as this works well with all paints, Tamiya airbrush cleaner doesn't work so well with Vallejo paints. I have also found that although Vallejo Air is good to spray from the bottle that sometimes I still think it with one or two drops of Vallejo thinner.

Learning to double action correctly will also enhance your painting experience and result in the airbrush not clogging up as quickly. This is a simple method that often is not adhered too. You start the airflow by pushing the trigger in, then whe you are ready to paint you slowly bring the trigger back to release the paint into the airflow, the common mistake whe you are finished is jut to release the trigger, however this will cause the paint still inside the tip to dry on the needle and clog the tip quicker, instead when you finished push the trigger forward to cut off the airflow and leave the air flowing for a second before them coming off the trigger, this will help to flush through the paint that has been sucked through and result in less of a build up.

Hope this helps

Thanks Dave and Chris for your time, still waiting for paint to arrive then I will have a go.