As Qvaak says, there is not a lot out there. There are some good recordings of David J. Peterson speaking High Valyrian at
http://jeffrubinjeffrubinshow.com/episode/88-game-of-thrones-cookbook-languages/, but the two full sentences he gives are silly fan requests that he translated on the fly, and has repeatedly said should not be considered canonical. They're still useful in terms of his pronunciation though.
You can also get him saying a couple words and short phrases (for both Dothraki and High Valyrian) at
http://www.whosay.com/explore/tags/stormofwords and
http://www.whosay.com/explore/tags/conlangfc.As far as High Valyrian is concerned... I find that the way Mr. Peterson pronounces the "rising diphthongs" is very difficult to emulate, and I doubt a recording of anyone else, myself included, will get that right. That is why those recordings of DJP himself are so important.
However if you're not that picky, there's also some recordings at
http://jdm314.livejournal.com/199528.html of two of my friends reciting a poem I wrote in High Valyrian. It's poetry (so it won't sound quite like the spoken language), and actually neither of the two readers has studied High Valyrian (they just happen to be really good at pronouncing unfamiliar texts), so take those with a grain of salt.
