The Santa Barbara Corpus of Spoken American English (SBCSAE) is good resouce for your purpose. You can download the corpus below (digital audio files also included): http://talkbank.org/data/Conversation/SBCSAE.zip
This version of SBCSAE applies CHAT annotation format for use with CLAN, which can be downloaded from the CHILDES or TalkBank sites: http://talkbank.org/software.html
You should of couse get familiar with the symbols used for encoding speech and prosodic features used for SBCSAE, developed by Dubois et al - I think there is a copy at this site, just search for it.
You can of course download a tool from the above link to convert the CHAT format to XML and then explores the XML version using Xaira.
You can also remove all annotations and leave transcripts of the spoken data if you can do a little bit of programming.