Let's say I have an Excel spreadsheet that looks like this:

    A         B         C
1 Item A   Thing 1    Whatsit A
2 Item B   Thing 2    Whatsit B
3 Item C   Thing 3    Whatsit C
4 Item D   Thing 4    Whatsit D
5 Item A   Thing 2    Whatsit C
....
5000 Item E  Thing 6  Whatsit X


And in another spreadsheet (or a worksheet, or a range somewhere on
the same spreadsheet - it doesn't really matter where), I have a list
that provides additional columns of information about the items in
column B:

     A		B	C	D
1 "Thing 1"	Blue	White	Red
2 "Thing 2"     Green   Yellow  Purple	
3 "Thing 3"	Black	Blue	Beige
4 "Thing 4"     Grey	Brown   Orange

I need to incorporate the additional information in the BCD columns
into the original list, in a relatively automated/batch manner.

So at the end of it all, the consolidated sheet should look like the following:

    A         B         C            D       E        F
1 Item A   Thing 1    Whatsit A     Blue    White    Red     
2 Item B   Thing 2    Whatsit B     Green   Yellow   Purple   
3 Item C   Thing 3    Whatsit C     Black   Blue     Beige    
..etc..

What's the best way to accomplish this type of "lookup and insert"
functionality (using Excel)?

I suspect there is a relatively simple answer to this - if not and
I've mispriced, please let me know.

Thanks.