Steve,
Where shall we start?
First just a couple of things about SketchUp in general. When you see faces colored blue in the style you have chosen, you are seeing the back sides. When I work with students on this side of the pond, I tell them to think of A/C grade plywood. The A face is the good side which we want to see. The C face is the not good side and we want that to be hidden on the side away from us. You should work to have the white side exposed and the blue on the other side. Now, in your case, since the walls have no thickness it would be normal to see all blue faces in your view of the outside of the room.
Next, what you see on the outside is normal for the way you approached drawing it. This method can be quick but it makes it difficult to make modifications and certainly more difficult if you wish to make construction docs later.
So here's how I would approach this at the proposal stage which it sounds like you're at.
1. Draw the floorplan of the room and the walls to the proper height. I would leave out the ceiling and I'd probably really only draw a little bit of the left and right walls at least to start. If there are unmovable details such as windows, trim, electrical, etc. Put those in. You don't need a lot of detail at this stage so keep it simple.
2. Make the room a component.
3. Mentally divide the project into sub-assemblies. For this one I would say there are base cabinets, maybe a "counter top" and the shelving above.
4. Draw in the base cabinets starting with a rectangle on the floor and using Push/Pull to bring it up to the height just below the counter top. Use the Line, Rectangle and Push/Pull to draw details such as the base molding (add a 'u' to suit.

) and the frame and panel doors. Will there be face frames or are these the frameless kind?
5. When you get the base cabs pretty well roughed in, make them a component. Triple click on the cabinet with Select to select all of it before making the component.
6. Draw a rectangle on the top of the cabinet, pull it up with Push/Pull, pull the front edge out a bit if there'll be an overhang.
7. Make the counter top a component.
8. Repeat the process to make the shelves above. You can draw a big box between the counter top and the top of the wall, add lines for the shelves and use Push/Pull to eliminate the waste.
9. Make the shelves a component.
At this point you should have something to show that will get the point across to the client. They should be able to understand what you understand them to want. You can modify parts of the project without affecting other parts. For example, perhaps they decide they'd like drawers in the center section of the base unit instead of doors. You can open that component for editing (don't explode it) and make the changes as needed.
Once you have the final sign off from the client you can start adding whatever details
you need to build the thing but that'll be for another post. Let's get the proposal drawings finished first.
One note about proposal drawings. This is just my preference but I like to use some sketchy line style early in the process to avoid giving the customer even the least idea that the design is fixed, carved in stone, if you will. I also tend to avoid adding materials leaving the drawings as simple line drawings. As the design of the project gets farther along and closer to finalized, I tighten t he line style up. I also like to keep details to a minimum early on so if the client walks after getting my early drawings, another cabinetmaker doesn't get enough details to simply hand the client a price. I don't mean to be rude but if the client is going to shop around, I want the other guy to do some work for the job, too.