While it not used as widely as in the past there is still some programming done using BASIC and its variants so it's not really a bad language to be familiar with.
On-line there are still several sites which offer tutorials which you might wish to check out:
http://www.petesqbsite.com/sections/tutorials/beginners.shtml
also
http://www.qbtop50.com/
If you are looking to study BASIC programming on your own I would suggest you check on-line for one of the older books on the subject. The book which I found most useful when first starting was the following:
USING BASIC 2nd EDITION
Phil Feldman & Tom Rugg
QUE Publications ISBN: 1-56529-140-9
You will also need either an interpreter to run the code or a compiler produce an executable file. To start with I would recommend you download the "olddos" file which contains Qbasic interpreter and the Help file at the following link:
http://download.microsoft.com/download/win95upg/tool_s/1.0/w95/en-us/olddos.exe
This will get you started with out a great deal of cost yet permit you to learn programming logic which can be used with other languages if you decide you find wish to continue.
If you wish to purchase a modern, Windows compatible, commercial compiler you might wish to check out the following link:
http://powerbasic.com/