Morrus, I work as Chief Operator at a local community radio station here in Kansas City, and I've worked on a couple of podcasts in my time. If you need any help, let me know.
Let me say up front that I believe that a good quality production is key. For an example of what I'm talking about, listen to Slice of SciFi sometime. That's one of the best-produced podcasts out there.
I listen to a lot of RPG podcasts, and there are some that could be better. WotC's D&D podcast
should be the best one out there, but it's a far cry from it. Their audio levels are not even, and it sounds like they have everyone use the same mic. It doesn't work that way. Then there are shows like the Tome Show, where you have excessive pauses. Pacing is key to keeping your audience coming back. If you have long pauses, people won't listen. (Not trying to pick any any one podcast, just pointing out various mistakes I see out there from time to time.)
Half an hour is a good time. Don't go any longer than an hour. I like the Dragon's Landing Inn podcast, but they go long and I can't do two hours.
As for networks, the War Pig Radio guys are a good bet, especially being tied to Fear the Boot, but I'd also recommend talking to Farpoint Media, the guys behind Slice of SciFi and Dragon Page. The Dragonlance Canticle is part of their network. It would give you a lot of exposure.
Just a warning, podcasts seem like a simple thing to setup but they're anything but. Another website I frequent has a regular podcast and they muddled through months and months of learning curve, producing very crappy quality podcasts until they finally felt the only way they could produce anything decent was to buy $6,000 worth of gear and hire out a soundproof studio which costs another $1,000 a month.
You can get by with a $75 mic, Audacity (free), Levelator (free), Skype (free), and $25 for the Pamela add-on for Skype. It may not be quite up to broadcast quality, but it can produce a fairly decent sound.
As for all the soundproofing, that's good and what not, but on a budget, you can do something like what podcast author Scott Sigler did and record in a clothes closet. By doing so, the clothes on the hangers function as soundproofing.
And no, you don't need to buy a $10,000 - $15,000 audio board. Those are nice, true, but some good editing in Audacity will eliminate that cost.
So yes, you can podcast from your home on a budget. Just be aware of your audio levels, keep it tight, and you're good to go.
Best of luck!
