Soundproofing my home office

[Jadi T.]

I'm a virtual assistant and I've been working at home since 2009. Currently, There are lots of dogs in the neighborhood that dogs are too noisy at night. Most of my tasks were in inbound or outbound calls so those noise will affect much my job. So, I was  thinking of soundproofing a part of my room only for my home office to avoid any noise destruction from the outside. My question is, what do most people use or like the most effective material used for soundproofing? I badly need it so I can start accepting client calls. Please recommend. Thank you!