Georgiya, a podcast is an audio based conversation that talk about a topic like politics, culture, art, history. You can listen to it while doing chores or walking because it's audiobased. It's a great way to learn about a country/region or a culture while practicing your understanding of the language.

Well, I guess it depends on what your goal is.  My goal is to be a better speaker.  I make it a priority to have two italki lessons a week.  I spend time each day reviewing what I learned in each class.  And I also watch TV to improve listening.  My favorite shows right now are Betty en NY and La Reina Del Sur.  Betty en NY is realtively easy to follow while La Reina is a bit more tough.  I record them on YouTube TV and can watch/listen anywhere.  Podcasts / transcriptions, etc are kind of at the bottom of my list, though after I have gotten through the above mentioned.  At the end of the day, you have to do what you enjoy the most.   I used to spend a lot of time reading, but decided it is more useful and practical for me to master what I speak about in everyday life, as this is what I use most often.

Yes, I have been listening to Radio Ambulante for years.  I don't have a favorite episode.  The best part about it is that if you don't understand something that you hear, you can always go to their website for the transcript in English or Spanish.  The only negative for me is the length.  I wish the podcasts were shorter.  It takes time to really listen and absorb each episode.  But it's a great resource for learners. 

They are generally interesting and they come with  transcripts, English and Spanish-- that is fantastic. The downside for me is that many weeks many of the people interviewed have very heavy accents that are very difficult to understand,  (and I can understand the hosts just fine), and speak a lot of slang, peculiar of course to their region--so much of the learning effort is of marginal use. Occasionally they do have guests that are somewhat difficult to understand but are at least intelligible. The recent Toy Story episode for example had a Cuban woman talk about Christmas under Castro but her accent was not that strong and with extra effort I could understand her--just the level of difficulty I need. So RA in that way is like a lot of resources on the net: lots of potential for learners  but you may not be at that level yet.