So you wanna do a podcast? Awesome! Podcasts are fun. Luckily for you, the equipment to do so, at broadcast quality, has never been cheaper or easier to use. I can't help you with the content of your podcast (unless you're Louis CK, nobody wants to hear your 3 hour rants, on anything), but I can help you make it sound good and that's half the battle. You could have the best content in the world, but if it hurts my ears, I ain't gonna listen to it. This guide is focussing on doing a podcast with other people in the same room, kinda like a mini radio studio, because that's what I'm asked about the most. Plus they're the most fun type of podcasts to record!
The most important thing you need is a location to record, that has a good audio environment. The aim here is to record somewhere with lots of soft surfaces and in a relatively small room. A big room will introduce echo, and a room with hard surfaces will create reflections - these are bad. You probably can't make your own soundproof booth, but some simple acoustic treatment will make a major impact, more than buying a fancier microphone.
If you're in a large room, create a smaller room inside of it with tripods and thick blankets. If you're after something more permanent, stick acoustic tiles on the walls of your room. Basically, you want to be enclosed in a padded cell. Check out this YouTube video of someone reviewing acoustic blankets:
This video is also good at demonstrating what room acoustic treatment means:
Wrap your room in as much soft stuff as you can and you'll have a great sounding podcast, regardless of your gear. Obviously, you want to turn off any fans/air conditioners/noisy computers/external HDDs, etc. silence is required except for the voices on the podcast.
USB microphones are awesome for doing quick recordings on your computer, but if you want to use multiple mics at once, then USB mics are useless. You need a mixer and some XLR microphones. There's hundreds of microphones out there, but there's some particularly suited for audio and are excellent bang for buck. There's two types of microphones - condensor and dynamic. Don't worry about the pros and cons of each one, what matters is the condensor mics need phantom power and dynamic mics don't (generally), so if you grab condensor mics, make sure the mixer you're plugging them in to supplies phantom power on the XLR socket you plan to plug the mic into.
If you're really strapped for cash, the 'Behringer C-1 goes for only $60 and sounds perfectly acceptable. If you've got a little more money to spend, the Audio Technica AT2020 is great bang for back at $129. My favourite is the Rode Procaster, when used with a shockmount (which absorbs vibrations), it's as good as any broadcast mic out there and only costs $195 (the shockmount is $49).
If you're really well off for cash, the Shure SM7B and the Electrovoice RE-20 are in pretty much every radio studio in the world.
This video from Rode is an excellent guide on how to talk into your microphone properly, regardless of brand or type:
You need a stand for the microphones too, so grab a few desk mount stands, like these from Swamp Audio. If you want something more permanent, the Rode PSA-1 microphone boom arm can be clamped or drilled into a desk and is perfect for setting up your own radio studio. Oh, and don't forget XLR cables - one end goes into the mic, the other into the mixer. You need one cable per mic.
MIXING & RECORDING
All those microphones plug in to a mixer. Traditionally, you would plug the mixer into a computer soundcard and the computer will record it. In the past year or so, there's a bunch of mixers available that record directly on to their own flash memory. I love these units because it removes the computer from the recording equation. Computers like to crash and make noises and generally get in the way.
The Zoom R16 and R24 are the best of the bunch. They're priced very well, with the Zoom R16 going for only $400 including postage off eBay from the USA (its around $600 locally). Just plug in the mics, insert in an SD card, set your levels and press record. When done, take the SD card out, chuck it on your computer and edit away.
Here's a review of the R16 from YouTube. The R16 and R24 are similar, but if you need more than 4x phantom power XLR inputs, get the R24. You can also plug either one into your computer and use it as a USB mic interface *and* it can run off a battery. Very handy little things:
If $400 is still too much cash, there is a cheaper way to achieve similar quality, albeit with more complexity. Grab a cheap Behringer mixer, the XENYX 1202FX wil do fine ($139) and get a 2x RCA to 3.5mm cable and plug one end in to the line-in socket on your computer and the other into the Tape Output on the mixer. It won't sound as nice, but it's fine if you're on a budget.
At least one person in the group should have on a pair of headphones, to make sure everyone sounds good. Get a pair of comfortable headphones (the AKG K44 studio headphones are only $45), plug it in to the headphone socket on your mixer and that's all you need to do. If you want everyone in the group to have a pair of headphones, so everyone can monitor their own audio, get a headphone amplifier like the Behringer HA400. The headphone amp is also useful if you're playing back audio in your recording session (e.g: a pre recorded clip or a phone call) and want your fellow podcasters to hear it, as you can't use speakers - they'll cause an echo.
I'm not going to give you a tutorial on how to edit audio, but here are some handy tips I've learned that are not common knowledge:
Record at 16-bit, 44.1kHz and in mono. Mono audio is fine for a podcast. Putting one person in the left channnel and another in the right is plain annoying. Keep is simple, you aren't good enough to toy with audio effects if you're reading this article. Don't bother putting each mic into its own channel either. If you're using the Zoom R16 for example, just downmix it to audio directly on the device.
Use the Levelator. I love this thing. Just feed it your raw audio before you edit it and it will even out people who were talking quiet and those shouting in to the mic. It's works so well to make your group conversation sound less jarring to the listener.
Audio editing programs can be difficult to use, so just use whatever you're comfortable with, it makes no difference in the end what app edited the show. I personally like Adobe Audition.
Choosing an exporting format for your show can be tricky. I personally like to keep it modern and use HE-AAC at 48kbit/sec and mono 44.1kHz (which everything made in the past 5 or so years supports), but for the widest compatibility, just use MP3, CBR, 64kbit/sec, mono 44.1kHz. Any higher bitrate is a waste of time for audio only podcasts.
This also isn't a tutorial on how to put your podcast on the Internet. But if you want something easy and quick, use Libsyn. Great service and works well. Make sure you write a proper synopsis for the episode/show - people like to know what they're gonna listen to. Good cover art for your podcast is important as well. Don't leave it blank.
Hope this helped you get a grip on podcasting! If you do end up making a show with the help of these notes, please let me know, so I can take a listen. If you have any questions, feel free to post a comment and I'll try my best to answer it.