Many parts of the site require a location to work properly. The actual selection of a location is that same for various parts (like setting your home location, or adding travel plans). This page is just about selecting the location. To do something with it, please click the link to the relevant page.
To set a manual/saved location for the first time, click the 'set new location' button. A map will open (it shows your home location, or if you don't have one yet, New York as the default start location). Above the map, there is a text box, which will say 'New York' or 'search for location'. If you type in your town name, or zip/postal code you should get your location come up as an option below where you're typing. Currently only three choices pop up, which we need to increase. Type in your search location. If the correct option does not appear, add additional info, for instance, 90210 (the most famous zip code in the USA if you're Gen X) does not return the correct result immediately, but if you add 'beverly', you get the right location to chose.
Click on a location in the drop down menu, and the map will move to that location, and a pin will be displayed. That's the selected location. You can move that pin around by dragging and dropping it.
If the text location system isn't finding the place you want, you can drag and drop the pin to any location in the world. You can zoom the map in and out with the scroll wheel on your mouse, or with the usual two finger 'pinch' on a mobile device. There is also a + and - zoom in the bottom right of the map. Find the map location you want, drag and drop the pin there, and then zoom back in to set the location as accurately as you wish. You can also click and drag the map around, so as to keep the pin within the displayed map.
Once the pin is in the right location on the map, click the 'use this location' button below the map.
This will then return you to the originating page, such as account settings or add travel plans.