Here are some very basic points regarding locations:
(1) The land in Second Life is broken into square regions, each with a name. Within the region, land is broken down into different shapes and owned by SL residents. The landowners can also give there areas a unique name. For example, Just Genealogy is in the Wollah region. Live Roots is in the Assiettes region. Regions can be rated (A)dult, (M)ature or (PG).
(2) You can "bookmark" a location by creating/receiving a landmark (LM) to the area. Objects and people in SL can give you landmarks, or you can create your own (for the location you are in presently). From the top menu, select World -> Create Landmark Here.
(3) Your landmarks can be found in your Inventory (click button on bottom) in a Landmarks folder. You can delete ones you no longer want to keep, and you can drag them to your friends if you wish to share them.
(4) Every SL resident is permitted to have a "home" location. This home is the place where you will appear whenever you login, and is also a quick "escape" (using Ctrl+Shift+H) if, in the unlikely event someone is bothering you. To set your home to the location you are currently in, from the top menu, select World -> Set Home to Here. You are welcome to set your home to either the Just Genealogy or Live Roots areas.
(5) You can search for locations using the Search button on the bottom of the screen and then selecting the Places tab. You may filter out the Mature and Adult areas if you like (checkboxes in upper right). Keep in mind, landowners must pay to be included in this search, so if you don't find a place that you know exists, it doesn't mean it's gone.
One TWIST with landmarks. The landowner can chose where visitors arrive on their property. While you may create a landmark anywhere on their property, when you teleport in, you will always land in the place they designated. Landowners have the option to allow visitors to land anywhere as well, so you will have different experiences with landmarks are you travel around.