Hi there,
A good starting place is my asking what sim are you going to be creating a skin for? You've got Photoshop, which is all you need for the painting and creating.
Once we know what sim you have interest in it's easier to give directions.
If perchance it's the IL2 series, then all you need to do is choose an aircraft model you'd like to paint, download a template for the plane from our downloads section, and you're 99% set from there. Consider any of the template on the first page here:
http://www.simmerspaintshop.com/foru...hp?do=cat&id=5
You'll see each already has some paint applied to a certain layer for each part. Just go in and on those layers and paint the camo schemes you'd like, then move to any markings layers and do the same. Any part of the templates can be repainted how ever you'd like to.
For any of the smaller points releated to techniques, we've probably got some articles already uploaded to help you, just do a search here:
http://www.simmerspaintshop.com/foru...m33-tutorials/