[Genome] human gene expression question

[DeCerbo,Joshua (stu)]

Hello all - I have generated a table of DNA elements that I am interested in, and I want to correlate this table with gene expression data. I have my table stored in the Galaxy browser, where I perform most of my mysql-type of analyses. 

I have been looking at using the GNF altas data or the AffyAllExon data in this regard. I believe the exon-specific data will be more useful for my analyses, but I'd like to look at both before making that conclusion. However, I am having trouble understanding how best to use this data, or upload it to Galaxy. Here are my specific questions:

1) I want to use tissue medians for my analyses. Where are these found? Do I need to generate these? If so, how?
2) After uploading the chip data in the raw into Galaxy, I can see the vast number of experiment replicates. However, how do I figure out which tissues or cell types the individual replicate data (separated by commas) come from?
3) In the AffyAllExon data, what is the difference between the "Score" column and the "expScores" column? Which should I use in my analyses?

So, in essence, I am having trouble getting the expression scores I want and knowing where said scores come from and what they represent. Any suggestions?

Josh DeCerbo