Here are some of the answers to your questions.
How to best use the Google Map?
The answer is going to be subjective. You can use google maps for finding places, finding direction or simply to mark your business or home on map. How do you want to make use of maps in such case depends on your requirements. My best use is to track the places I have been and places I am yet to explore. Your usage scenario could be different.
How to identify the location of my house in the Google Map?
You get the option of either aerial view or the hybrid view. Zooming close to visibility region closer to your house, you can figure out the top view of your house. For example, first find the known place nearby your house and then zoom and scroll over to get close. And from here you can mark your home so that either you can find it later or for public marking.
Does Google Map record the location of each and every search ?
Yes. Google records every interaction being done on their web properties. This way they improve the quality of their product. Also they improve their search suggestion and configuration.
How to know the latitude and longitude of a place or location?
Most of the popular place if searched on Google web search, can show you latitude and longitude on the right hand side of search page. For example searching for some lake in ladakh will show you information bubble on right hand side of google. If your location doesnt have that then you have to find other places like travel apps or wiki. There is also option to find those co ordinates on wikipedia if the place has page on wikipedia.
Is there a device in finding that and name of the device?
Most of the GPS devices have the search option that shows you co ordinates. Most of these devices are expensive but can be handy for those who are frequent traveler. I'd suggest getting Garmin GPS if you can. They are costly devices but can give you what you need from specific location. They also have voice guidance system in them.
How does this work Technically, for sending and receiving the information? Where and what calculations are done ? Is it possible to do projects based on the Google Maps?
Google maps connects with a central server that regularly updates the location based on the google's collection of data. Google server makes use of the big data to store the entries related to the location. And they return the content based on the user requests. You can use the Google maps API to perform the distance calculation, find shortest path between places, find alternate route during traffic jam etc. Yes and it is completely possible to do the projects based on the google maps. There are many companies that make use of the google maps data to do the business listing, supplier tracking, logistics tracking, travel directory management and GPS usages.
How many technologies does Google posses like this ? How to know who has used maximum in the Google Maps ?
Apart from Google maps, there are many other location specific technologies google possess. For example google has started physically mapping museums, artifacts, locations as a first person view. You can check the demo of this tech in Google arts app. Another popular tech is known as Google earth, that is bigger version of google maps. It gathers all the old and updated data about earth. Even the smallest change is now being recorded and mapped. Google moon is similar project that keeps track on moon changes, moon's craters and other physical changes on moon. There are few other enterprise and government level projects not open to public but are shown in Google IO.
Google has public level, developer level and enterprise level API. So the sites that make use of google's map api or earth api get API key that shows the usage count. However this data is not public. So it's hard to find out who used it the most. Enterprise who use their service sign NDA on not making such data public.
