My blogs will give insight into all aspects of DYI, from steeping to what supplies to have on hand to a basic walk through mixing your first E-juice.
E-Cigarette Forum - dannyv45 - Blogs
Then read hoosier's blogs. These blogs concentrate on fine tuning your mix and give insight on additives.
E-Cigarette Forum - Hoosier - Blogs
Then read Boletus's blog's. These blogs concentrate on formulation of nicotine baces regarding proper calculations methods for figuring Nicotine concentration as well as safety.
E-Cigarette Forum - Boletus - Blogs
Then read Ginger's book "E-Cigarettes 102: DIY e-liquid". It is a book which I've contributed to that delivers an in depth easy to follow guide in the art of DYI.
E-Cigarettes 102: DIY E-Liquid
I also recommend viewing VPLive Vape Team Episode #82: DIY Safety and bookmark it for future reference. It explains safety in all aspects of DYI.
VPLive Vape Team Episode #82: DIY Safety
Then read the stickies at the top of the page.
This will explain a lot of the how's and why's.