I've found some pretty good podcasts recently through itunes.
Here are some:
「ねえ, ねえ聞いて!」 - a young girl who talks about a ton of different topics, from healing through laughter, to the Chinese zodiac, from nostalgic school supplies to kanji/word origins/trivia. It's also very, very easy to understand. She's so fun to listen to, and she doesn't sound annoying/doesn't particularly have a high, screechy voice. (when you're looking for it, you'll see a picture of her cat). I'm so glad I found this podcast -- I'm sure many here will enjoy as well.
「nanalife」- This is a nice, calm podcast aimed for women, but there's nothing wrong with men listening as well

It's very relaxing and most of the topics are related to health, beauty, aroma therapy, aging, etc. Very easy to understand. Good for if you have a play list designated for sleeping/relaxing.
「新刊ラジオ」- I couldn't find this on itunes again, so here's the link to download online:
http://www.sinkan.jp/radio/index.html . You'll probably get an itunes link there too.
This podcast is all about book reviews. You will even get what seems to be a portion of the audio-book thrown into the podcast. There are lots of interesting books to choose to and hear about through the podcasts. Also a good opportunity to find out about Japanese books, of course n_n
「スターウオッチングエクスプレス」("Star-Watching Express") - Astrology podcast

Great program with nice music in the background. You can tell he's so enthusiastic about looking at stars and planets, so it's fun listening to~
「神戸市心かよわす市民運動」- This podcast is of people reading letters from children. There's one about a kid talking about his autistic brother, another one with a kid talking about his grandpa who uses a wheelchair and another one about kids who are teased. Very easy to understand. I just wish the guy they use to read them didn't sound so newscaster-like and impersonal. There's a woman who reads some of them and it sounds better.
「日本の童話」- One of the narrators for these is so funny~ she narrates 「キャラメルと飴玉」and 「二つの鞄」and her voice is hilarious~ please look for it! ^^
「平良とみの沖縄タイム〜なんくるないさ〜」 - You may have to get through lots of intro music or ads and things like that to get to the talking, but this is a very interesting podcast done by a older lady in Okinawa. She talks about many things related to Okinawan culture -- food, health, lifestyle. She sounds so sweet and kind~ it's always nice listening to this lady.
Tip: Best way to find Japanese podcasts is to switch your iTunes store language to Japanese. On the bottom of whatever page you're on in the iTunes store, you'll see a flag (of whatever country you're in, most likely). It'll be in a circular shape, on the right hand side. Click that and you'll bring up all the flags. Find the Japanese flag and click it.