Scaling,
I know I have to be missing something, I just can’t seem to find the right answer, and yes I am new to sketch up. I want to draw a small part, some edges are 1/10 of an inch. I obviously can’t draw the part that small so how would I go about drawing it in a reasonable size but labeling it with the correct dimensions? I know this involves scaling but I can’t find clear instructions on using this function. If you could help me, with a simple example that would be great but also if you could show me where the instructions are (for this subject) within sketchup that would be even better so I don’t have to ask what amounts to pretty simple questions in the future. Lastly if that can’t be done is there a way to override the dimensioning numbers, I still want to use the dimensioning tool but I want to draw the sketch to a reasonable size and still label the dimensions with the actual size for the prototype maker. Thank-you!
While SketchUp won’t make very short edges, they can exist. My approach to drawing small objects is to start by drawing what I can at the correct size. Often that is something like a drawer pull or knob for me and I’ll need to do something like running Follow Me which winds up leaving holes. Before I run Follow Me or other operations to create the geometry, I’ll make a component of what I’ve got, make a copy and scale that copy up. This leaves the original in its original location. Then I open the scaled up component and do what needs doing. When I’m finished, I close the component to get out of edit mode and delete the large copy. Then I can return to the original, properly sized copy and use it or dimension it.
It will help to make sure you have Precision set as high as you can go and disable length snapping in Window>Model Info>Units.
Here’s an example of something I’ve drawn using the method I described.
There are some edges in the knurled area that measure .008 in. long.
@DaveR, what an interesting approach about scaled component copies! I should give it a try sometime in the future. 
I use this method frequently. It beats scaling up and then scaling back down. If you do scale up and back down, you want to use the same scale handle for both scaling operations.
A few years ago a guy sent me a small model he was working on to see if I could figure out why hitting Zoom Extents made it disappear. It turned out that it wasn’t really disappearing. The main model (a chessboard) was about 3 miles from the origin and there was a tiny, unrelated line segment about 10 feet from the origin in the opposite direction. Hitting Zoom Extents made SketchUp try to show both areas.
It turned out his chessboard was located so far away from the origin because he had scale up and down several times while working on small details and managed to “walk” it off into the distance. After deleting the line segment that was unrelated and moving the chessboard back where it belonged, everything was OK.
Now there is something to hold parts together with . . I like them, As I am using Tab and Hole to hold BIG Parts together. . Wonder if I could get that printed out on 3D printer . . Do you have a single one of these ?
I expect it could be 3D printed. It is a solid component after all. The model isn’t available to give away, though. Nothing preventing you from drawing your own pin if you want.