Your full training regimen will begin tomorrow. Today will be spent doing a number of administrative chores and introducing you to some key people. We will start at the Finance office where you will complete forms for taxation and pension purposes and receive your security passes. After that we will introduce you to our resident nurse who can be helpful and dispense pain relievers and so forth for annoying but not serious conditions. After that we will stop for luch in the cafeteria which has very good food at specially discounted prices.

Is it okay to put a comma before the each word where, who, which in the paragraph as follows:
We will start at the Finance office, where you will...
After that we will introduce you to our resident nurse, who can be helpful and...
After that we will stop for luch in the cafeteria, which has very good...

Thanks a lot!

Actually, all three require the comma, Jey.

Could you give me more details on why the three sentences without commas are wrong?

Here are two situations.

1. The writer wants to add information about the finance office, the resident nurse, and the cafeteria. This information is extra. It's not necessary to say, but it adds to the overall picture. When the writer wants to do this, he creates what we call appositives, and the cue to the reader that an appositive is coming is when that comma is placed before the appositive begins.

Let's look at these three again. The parts in bold, including those commas, are the appositives:

the finance office, where you will complete forms for taxation and ...

our resident nurse, who can be helpful and dispense pain relievers ...

the cafeteria, which has very good food ...

As you can see, the appositives, the parts in bold, add extra information, and the comma that precedes the appositive let's the reader know that this extra information is coming now.

2. The writer wants to show exclusivity. That means he wants to show that what he's about to mention is the only place or the only person that the information applies to. The information is not extra in this case; it's necessary to identify what it describes. In this case, the writer will not use those commas.

the finance office where you will complete forms for taxation and ...
(implying that there are other finance offices that do other things)

our resident nurse who can be helpful and dispense pain relievers ...
(implying that there are other resident nurses who may not be so helpful and do other tasks)

the cafeteria which has very good food ...
(implying that there's at least one other cafeteria that has bad food)

As you can see, Jey, the exclusivity created by not using those commas is really very silly in this passage, but it may not be so silly in other cases. For example:

Next weekend we're going on an architectural tour of the New York theaters where the first Broadway musicals were staged.

In the sentence above, the writer wants exclusivity. The information about those theaters isn't just extra information; it clearly describes the specific theaters they will be looking at.

I hope this will help you see when to use and not use that comma, my friend.