I’m starting to dive a little bit into electronics and embedded programming. So I’m wondering about the biggest or most well-known electronics forums/communities. There seems to be quite a number of them.
Bonus question: Anyone have a good PC-based oscilloscope to recommend? 
Have a look here:
Lots of really knowledgeable and helpful folks.
My favorite is the eevblog forums, and I’m pretty sure it’s the largest. Plus Dave (the guy who runs it) makes great videos that are informative and funny.
I would avoid the pc based oscilloscopes and go for a low-end benchtop. I have an OWON SDS6062. It’s a nice scope, but if I were buying again I would be tempted to go with the Rigol ds1102e. Consensus is that it is a better scope, but some say it is noisy (as in audible noise).
Ditto what breezman said. PC based O-scopes are the crap.
You didn’t mention what platform you’re going with, assuming you’re not starting from bare bones breadboard and PIC chips. If perchance it’s Ardiuno, poke around their forums. And while SparkFun is technically a store, their tutorials are quite useful.
Thanks for the suggestions! Probably going with the Rigol 1052E that the eevblog guy recommended, and hack it to 100mhz. Those videos are great. And he’s currently made 600 of them! It’s crazy!
I’m currently looking at the TI developers boards. The Ardiuno boards look a little bit too user friendly, as I’m trying to learn this more in detail.
I’ve picked up a few good used Tektronix scopes over the years. They aren’t PC based bu they are good scopes. You almost can’t go wrong with a good Tektronix scope and you’ll get the most bang for your buck buying used.
I also have a little DSO NANO scope. It’s a tiny little thing about the size of a small smart phone. It’s got really good bandwidth for the price and is a surprisingly handy little thing. The down sides - tiny screen, very unintuitive user interface, and crappy instruction manual. It’s a great little pocket scope. It’s not PC based but you can plug it into a PC and download data from it. Warning - it may not be obvious but this thing ships from Taiwan. Mine got hung up in customs for a bit so it took a lot longer to ship than expected.
I have a few decades of experience in electronics design and embedded programming, and there are plenty of other folks with a lot of experience around here, so feel free to ask questions here too.