Complete noob wants learn how to index

[lancet]

I'm using a mysql select from statement which can be seen below

mysql_query("SELECT * FROM massive WHERE hello = '$hello') 

Now my table called massive is very big so I learned that I need to use an index.

So how do I use indexes? I've looked them up but I still can't seem to figure out how they work and how I implement one.

Thanks.

[bretticus]

Here's an article to point you in the right direction