I have objects in layers above the object I'm trying to select. The above layers are 50% transparent so I can see the object underneath that I want to select, however clicking on it or alt clicking only selects the objects in the layers above. THe fastest way I can sind to select the object underneath all of those layers is to either lock or hide the layers above. I wish there was a way to hide all layers but the one I'm working on, or that holding the alt key while selecting objects would work on multiple layers. It seems that the alt key/click combo only works on the current layer. Or if I could select the lower layers form the layers menu and then only objects in that layer could be selected.
Perhaps there is a way to do this and I missed it. I did read a bout selecting in inkscape... Any help would move me along much better. Thanks.

Alt + click can select across layers, as long as they aren't locked. If any layers or objects are locked, the objects in them will be ignored.

In certain situations, you have to be careful with the mouse....or at least, I have to be careful....not to move the pointer. If I happen to be positioned over a path, and I want to use Alt + click, and the mouse gets nudged AT ALL, it switches modes so that when I click it starts selecting nodes instead of objects.

I often use layers to help with selection, especially in complex images. And it absolutely is possible to hide layers. See the tiny eye icon? If you click on it, the eye will close, and everything in that layer will be hidden. At present they can only be opened or closed individually. But I have seen a feature request for 'hide all' so they could all be hidden at once...which would be awesome.

Oh, and also, you could use sublayers. Then you can hide all the sublayers at once, simply by hiding the parent layer! But there is one caveat for sublayers. If you ever need to move it out of the parent layer and into another, it can't be done....well, not easily anyway. But keeping that in mind, sublayers can be very useful