Review/Rating/Search script?

[focus]

I was wondering how do people make websites like this?
http://www.tripadvisor.com/Hotels-g294265-Singapore-Hotels.html

I'm planning to make a website that allows people to rate, write reviews and search by location/price but I'm not quite sure were to start and the best way to go about it...
I've seen scripts such as:
http://extensions.joomla.org/extensions/directory-a-documentation/directory/233
and
http://extensions.joomla.org/extensions/clients-a-communities/ratings-a-reviews/9070

which will help me with the review bit but what about the searching functionality?

Should i be using Joomla? If so, are there any similar scripts available or does everything need to be coded on my own?

Also how do i add stuff to Google maps like Trip Advisor has done?

Thanks in advance!