I think sending people directly to GNU Radio is a bit of a risk. Sending folks that just learned how to spell SDR deep into the bowels of DSP is a bit steep of a learning curve that many might equate with a brick wall.
A little over ten years ago (!) I got started with a windows box, sdrsharp and a cheap RTL-based SDR. Just cruising around the spectrum, clicking on signals that were interesting, cobbling together decoding pipelines and getting real results was a way better way for me. Getting started with software that works and interesting use cases you can get into with cheap hardware got me hooked and THEN I had something that I was genuinely craving an understanding of to drive me into GNU Radio.
Agreed, GNU Radio exists in this weird no-mans land where it works on low-level concepts wired up with high-level guis. Do not want. I want to playing with CubicSDR to zoom around the spectrum, then if I I need to do anything fancy with the data, switch over to signal processing and start writing code.