How to hold the Guitar?

Here is what you'll need.

a) A standard acoustic guitar (with six strings).
Go to your local music shop and talk to their staff. Most of these guys are very knowledgeable and will help you pick the right instrument.

b) A guitar pick
There are a lot of different types of picks. Againm the music shop staff can help you with this. Buy about a dozen or so - They usually sell the beginner picks in packs of 10/12.

c) A chair without arms.

d) Lots of patience :)

How to hold the Guitar
You should be sitting comfortably, with your back against the back of the chair - Avoid slouching.
Remember the chair should not have arms.

The guitar itself is rested on the right leg (assuming. you’re playing right-handed) at its waist The guitar is slightly tilted back towards your chest. The thicker string should be towards you. If not, you are holding it upside down.

Another important point to remember is to keep a slight arch in your right forearm. Otherwise you will tend to pull the strings out to gain volume and in the process cause a horrible "thwacking" sound.