SolidWorks sheet metal is a tool for modeling in 3D and converting to 2D cut-patterns and the thickness is generally uniform throughout the model.
Sheet metal is commonly used for Sheet Metal, Paper/Cardboard, and Plastics when the raw stock is a flat sheet which can be formed into your desired model.
Not all things that can be produced from Sheet Metal can be modeled within SolidWorks; there are some features that SolidWorks cannot handle as well.
Closed Profile - Outer dimension of the sheet metal
Open Profile - Extrude bent profile
Where the bend starts is critical
As long as you think one step ahead, it doesn't really matter which you use, but it's not uncommon to get used to a certain type
If instead of making a bend at a current edge, you can bend the current body using Sketch Bend
Insert a sketch on a face
Use lines only, it is best to intersect the line with the current edges of the face you're sketching on
Select which face is fixed
Add angle parameters
Additionally, the Fold and Unfold tools may be used to individually address bends; these can be suppressed/configured as well
Similar to a Sweep, you can Miter Flange a profile around all the sides
To create a Flat Pattern configuration, you must first insert the model into a 2D Mechanical Detailed Drawing and check the "Flat Pattern"