If anyone sees this No Starch book (which is decent, btw, as one can expect from No Starch) and wants to dive in, start here: https://www.rtl-sdr.com/rtl-sdr-quick-start-guide/
There's a lot of garbage equipment out there and it's easy to buy something that does not work or creates spurious emissions or other weird interference and incompatibilities. Unless you know how to mitigate these issues with a deeper understanding of electronics and RF, you're going to struggle to get good results.
That site is easily the most comprehensive starting point for beginners, but read through it carefully before purchasing a dongle.
I second the rtl-sdr.com site.
There's a lot of cheap (as in not very good) stuff out there. I have 3 goto SDRs in my collection. The RTL-SDR.com Blog V4 dongle is a great--and affordable--starting point. You're only out ~$40 if you decide this isn't for you, but if it is, the 27 MHz to 1.6 GHz coverage will keep you busy. If you are a ham, or enjoy short wave listening, go with the Airspy HF+. Covers 0.5 KHz (I've seen reports of ultrasound experiments with this!) through HF, and VHF bands. For the price, this is the highest quality SDR I have. Great sensitivity, low noise. Rounding out my small collection is the Great Scott Gadgets HackRF One, which is pretty much a radio lab in a box. 1 MHz to 6 GHz, 20 MS/s (albeit at only 8-bit quadrature sampling), and can transmit. (As an added bonus their teaching videos are very good.)
BTW, I have no problems with running these 3 SDR devices on Linux, if that is a consideration.
Have you don’t any transmitting with the HackRF One? What was the experience like?