This one will be quick and dirty, and I got inspired when I was going through some old stuff.
My first home microphone was the Blue Snowball, a piece of gear that is still very popular today because it's a low cost, non-headset microphone. Right now it's sitting in a box in my closet, along with its sweet looking shock mount. It served me well for the time that I used it. I had recently graduated from college, and lost access to the sweet school studio full of RE-20's.
This isn't the microphone I would recommend for newcomers anymore, though, and for one big reason: monitoring. The Snowball lacks a headphone jack, which means that you cannot hear your own voice when you speak.
Monitoring is a big deal for lots of reasons. If you're in charge of the mix, you want to be damn sure your headphones are plugged in so you can listen on the fly. Otherwise, you'll go back to edit your recording only to find out that there's a terrible crackle you could have prevented, or one co-host's levels are way too low. Stuff like that.
If you're recording a podcast remotely over Skype, monitoring is still important. It's not enough just to hear your cohost(s). Hearing your own voice is incredibly important for developing and maintaining your microphone address technique.
Mic technique is probably beyond the scope of this article. It's hard to describe in text, and there are a lot of factors in play (How do you project? What kind of microphone are you using?). But all you need to know right now is that keeping a consistent angle and distance from your recording device is very important to sounding good. Slouching back, or turning away, will make you sound distant and muffled because your voice will fall outside of your mic's pickup pattern.
Much like that hiss or the maladjusted levels from before, if you're not listening to yourself while you record, you could go in to edit and find out that it sounds like you're broadcasting from the inside of a suitcase from across the room.
If you can hear yourself in real time, you can be constantly mindful and aware of how good you sound, and make small adjustments to make sure you keep sounding good. I feel goofy saying that "talking into the end of a thing" is a skill that takes time to develop, but it definitely is. It's a matter of building muscle memory and awareness, and you can't build either without feedback.
I hear two common complaints about this, which I will address individually:
1. I don't like hearing my own voice. I'm sorry, but you'll have to get over it. Grow into the callous narcissism that podcasting demands of you. For real, though, this is something that gets better over time. Everyone thinks their voice sounds like a tin clarinet when it's recorded, because they're not hearing it through a medium of bone and meat like they're used to. The thing is, if you wait long enough, you'll develop the mic technique you need to make your voice sound like you want it to.
2. When I listen to myself, there's a delay. And that's really, really distracting. Yeah, it really is. But it's also not normal. If you're talking into a Blue Snowball, and doing some kind of software monitoring through Garage Band or something like that, you're introducing software lag into the equation. The proper way to monitor yourself is by hardware... And that requires a specific kind of recording device.
Any mixer will have a headphone jack on it that gets you real time monitoring. But don't worry if you don't want a mixer in your life and on your desk. There are microphones that have 1/8" jacks built right in. Just tell Skype to use the microphone as both the Output and Input devices when you go to use them. The microphone will immediately play your own voice back to you when you speak, mixed in with whatever your co-host(s) are saying.
Here are the mics you want to look for. All of them have onboard lag-free monitoring.
Samson C01U Pro ($90). This is a great, inexpensive microphone. It doesn't look sexy, but it has great noise rejection for a condenser microphone. You'll need a stand for it, because the one that comes with it is crap. This is the microphone that Ben and David use.
Samson Meteor ($70). Another good pick. It doesn't sound as great out of the box as the C01U Pro, but it looks better and it has a headphone volume knob if that's your thing. Again, get a stand, because this thing is made for people with half-sized torsos. This is the microphone that Dennis and Kris use.
Rode Podcaster ($200). This is a great USB dynamic microphone, and I wouldn't hesitate to recommend it, in spite of its cost. This is the microphone that Gary uses.
Blue Yeti ($130). This is a very popular microphone that offers a lot of bells and whistles. I'm putting it at the bottom of the list because I think the Rode Podcaster is worth the extra $70, because the Yeti has a lot of the drawbacks of condenser microphones (including picking up more background noise). The biggest thing to recommend it is the onboard gain control. Nick uses this microphone.
Hopefully this is helpful to some people out there. Developing any skill takes practice and feedback. Don't let a bad gear decision deny you the feedback you need to get better.