'K. First go into object mode or face mode and select the object or a face from the object you want to map. Right click to open up the menu, then go down and select UV Mapping.
Now here's the real tricky part. You can let it UV Map by first going to Segment By and then selecting either Projection or Feature Detection. Projection works by grouping them in a front, back, top, bottom, left, right fashion. Feature Detection will try to group of the faces together, not always with the best sucess though. You'll have to try and see which works the best.
You can also specify which faces will be connected by selecting the faces then assigning them to a AuvChart (just right click and then select one of the AuvCharts). You get the greatest control there, but it takes forever to do. And you can't really save your progress there.
Once you have all that done, right click and go to Continue and select one of the options to get how it will project the UV Map. Unfold will take the map and lay it out flat. Projection will basically take a picture from the normal and call it the map. Spherical will distort the map so any specially done spherical maps can go on without any big distortion.
The best thing to do is keep experimenting with it and see what works.