Summary tables for data sheets

I want to create a summary table for a large range of data. For each day, I have logged 20 samples of airbourne particles. I would like to create a summary table that returns the daily average, becauase I am eventually going to chart the data along with the average and standard deviation. On "Sheet 1", I have my data, and on "Sheet 2", I want to have the summary table. I am somewhat familiar with the VLOOKUP command, is this the best tool to use?

For instance: in my summary table (Sheet 2), the first column is date (6/13/2011, 6/14/2011, etc). The second column is average for that date, and the third is standard deviation for that date. In my data sheet (Sheet 1), the first column is date (each date has 30 rows dedicated to it for each data reading) and the 4th column is the data reading. I want to combine those 20 rows for each date into my 1 row summary table on sheet 2.

So, can I type in a function to my summary table for the date "6/11/2011" that grabs the average reading of "sheet 1, column 4" for every reading that has the date "6/11/2011" in "column 1, sheet 1"?