I dont know anything about domain and all, where to purchase, what are the criteria etc... How much do I need to spend for the same, pls guide
Basically this depends on the website niche you want to start - but overall your charge will be following: Domain: $8-$10 web space: $3 - $10 per month the cost also lot depends on the kind of website whether it is database driven or simple html pages. I hope this helps...
It also depends on the purpose of the website: Personal or Business site. Because a business site is meant to be monetized, you will need some SEO research, and if you don't know SEO, you will need to hire someone to do it for you. There are a lot of providers, and some of them are really cheap. Do a search on google for "buy domains". Simple I hope this was helpful...
I know a few free websites if your not into a serious business or just wanted to create a personal website. You can try Weebly.com, it is more basically "drag and drop" and its easy for starters. If you want more flashy websites then you can visit WIX.com, they offer free FLASH based websites. They also offer premium services such as domains, design etc.
if you want to learn how.. grab Kompozer (search it on google) and start learning by going to w3schools.com or tizag.com