This is one of my worse skins, I have a blog on skin tutorial:
www.planetminecraft.com/blog/advices-on-making-skins-eggsman2292s-request/
There are more blogs on making and shading skins, here:
www.planetminecraft.com/blog/how-to-turn-your-skin-into-a-middle-earth-based-race/
www.planetminecraft.com/blog/a-short-tutorial-about-my-style-of-shading/
www.planetminecraft.com/skin/tutorial-making-realistic-hands-very-useful-must-see/
Plz, see mine, this will really help

You mean the application, there are many things, 2 are online and 1 is downloaded, compatible for mac and windows, there is one where you go on minershoes.com and scroll down, you will find a skin and a skin template, edit the template to the skin that you want then press on download and go on planet minecraft and go on skins then press upload skin and press on upload and select downloads then the skin that you just made on minershoes.com and wait for it to load then press save then you could add a description and put a name for your skin then upload it.

on the forum

Well, what should I do, I tried, I am not good at making animals, ask Roobus for that