Hello all,
What an interesting community! Allow me to describe a little bit about myself…
Years ago I found myself working in the electronics business, solving problems with microwave passive components. (The opportunity to work with computer hardware and software had presented itself, but I chose to stay closer to the physics side of electrical engineering.)
After a quarter century as a cog in corporate machines, I decided to try freelancing. So now, I can do whatever I like, as long as I can pay for it myself. 
My career was spent designing components such as antennas, filters, couplers, capacitors and coils, but now I want to learn about connecting radios to things and getting those things to talk to each other.
This is scary. I am leaving an environment where I know a whole lot (about a little) for a new environment where I know almost nothing (about a whole lot). Not only that, but I am not young any more, so learning is slower and more difficult.
The first thing I want to learn to do is to connect a GSM module to my computer, so I can send messages to myself over a cellular network without using my phone. Then I want to try to branch out into sending data over radio links. (I have a ham license but am not into rag chewing or contesting.)
Tools I have… Linear simulator, SPICE, EM simulator, solid model CAD, 20 GHz spectrum analyzer, VNAs, LCR meter, power supply, soldering equipment, lathe, hand tools. What I don’t have (yet): Oscilloscope, Knowing of how to connect anything to my computer that is not “plug and play”, knowing how to talk the talk or walk the walk.
Anyhow, I decided to post first in wireless/RF, because that’s where I am most familiar. After this post is excepted (if it’s accepted) I will try to contribute knowledge here as ‘payback’ for what I’m hoping to learn elsewhere.
If you have read this far, thanks. (If you can, thanks, mod…)