It's pretty easy in SolidWorks using sheet metal features.
Open a new part. Select Insert-->Sheet Metal-->Base Flange. This will begin a sheet metal part.
Note: Insert-->Sheet Metal is where you can find all of the sheet metal features.
Draw the base of your part and dimension accordingly.
Exit sketch, enter the thickness of material and any pther parameters you wish to change. I went with a 0.10" thickness and default settings. Click OK and you have your base.
Add an Edge Flange (Insert-->Sheet Metal-->Edge Flange) to the edge you want to extend. Select your flange length and click OK.
Add another Edge Flange.
Add another Edge Flange to create the two screw tabs.
Select the face for the slot and make a Cut-Extrude. Draw your slot and dimension accordingly. Exit sketch and select Through All. Click OK.
Select the face shown and select Cut-Extrude.
Draw and dimension the rectangular holes. Make sure the bottom edge of your rectangle overlaps the bottom of the part. I mirrored these since they appear symmetrical. Exit sketch.
Select the distance that you want these holes to penetrate and click OK.
Select the outer edge of one of the screw tabs and use the Hole Wizard to create and dimension your screw clearance holes. Select Through All and click OK.
You now have a complete sheet metal part. Notice that SW automatically created a suppressed feature called Flat-Pattern when you created your base flange. Unsuppressing will show your part as a flat sheet with all the appropriate holes cut and dashed lines for the bend locations. This may or may not be necessary for drawings, depending on who's doing your bending..