Olivier Masseau

Well to start I think a Numark Mixtrack Pro II is a good choice,just enough to learn the basics of djing without spending a lot of money.

It has a soundcard integrated and plugs directly into you computer by using the usb cable.

While learning your computer speakers or monitoring speakers (that you should have if already producing music) and a pair of in ear headphones should be enough.

For the software, it comes with Serato DJ Intro which is also good enough for learning.

Once you get the hardware and the sofware I suggest you read/watch tutorials. They are some good ones on youtube like this one:

There is also a nice dj course for beginners on this site: http://1.digitaldjtips.com/fast-info/
It covers everything you should know to begin in about 4 hours.
It is not free but I think it is worth it (You can find all the things it talks about on the Internet but it saves you a lot of time, time you don’t have to spend searching/curating).