UV's and Unwrapping, Somebody Help Me!!!

This is the most difficult part of 3D Modelling in my opinion, it follow's a complicated procedure and one slip could mean total destruction for texturing your model.

Unwrapping is essential for all pieces of finished 3D modelling, especially if you want to texture said model, unwrapping is able to convert a 3D model map into a 2D model map so that textures can be applied in Photoshop.  This process is slow and will take around 1/4 of the overall process.  
The main problem's with UV's is Distortion, Texture Space, and Seams, These are never perfect.
Distortion: Caused by the shape and size of the UV, organic shapes are more difficult than static ones.
Texture Space: All the space available that should be used, but never touching the outside, leaving enough space for everything to scale perfectly.
Seams: Eases distortion of the UV's, but need to be kept hidden from sight, because they stick out too much.

UV Checkers: UV checker do exactly what the name suggests, they help make sure that the UV's stay the same across the entire model.