The syntax for VLOOKUP (I'll try to make a point to put all formulas in caps when referring to them in text) is as follows:
So let's say you've got the list below:
You select that range (from Bob to Wigeon) and name it "SEARCH". (easy way to name a range is to select it and type in the name you want in the box above the row number indicators. The default in the box would be a cell like "D1")
Now, if you put a formula in cell D5:
and type "Robert" into cell C5, you will get "Wigeon" in D5. It looks at C5, finds it in "SEARCH" and returns the 3rd column for that row (counting the name as the first)
A nice feature of this is that using a name for the range allows you to very easily perform these searches across multiple sheets.