There are public domain readings for familiar tales like Aesop's fables, ancient Greek legends, Biblical passages, etc. By knowing the outline of the story at the outset, you can follow the gist of things and fit the meanings of many new words into your own pre-cast mental holes. You'll also get better at spotting cognates between the languages.
Do google searches for "Audio Cuentos" and there are many sites that can be helpful.
As for children's material - it can be helpful, but I often find that it is full of squeaky voices and distracting sound effects. And it may be paced quickly to keep a child's attention. Vocabulary can be surprisingly complex, too. After all, the typical 4 year old already knows a few thousand words.
Also, you can create your own Spanish audio, if you have some text that you want to practice listening to.
http://imtranslator.net/translate-an...speak/spanish/
Although it sounds mechanical, it's not bad for a free tool, and you can vary the pace of the dialogue. The best thing about computers reading for you - is that they are very patient, and won't get annoyed with you for asking to repeat again and again.
There's also this site. More voices are available, although you can't vary the speed. The "Spanish US Rosa" voice is not too fast, though.
http://www.acapela-group.com/