Building my tree
The following site provides a systematic way of achieving this goal: http://www.wikihow.com/Create-a-Family-Tree-Diagram.
There are other way of building family tree and the most common ones are through the use of computer software.
Family tree software
Online family tree software
Draws your printable family tree online. Free and easy to use, no login required. Add photos and share with your family. Import/export GEDCOM files. You need to register to save your work. Private. You choose who can view your tree.
Subscription required. Public
Multilingual, Registration required
Basic: free 250 individuals
Premium: 2500 individuals USD 2.39 monthly billed annually
Premium plus: USD 4.98 per month billed annually
Valid for 5 years.
Free. registration required. Private. You invite family members to contribute by adding missing members.
Family tree published online.
If you are already on facebook, click the above link, sign in and start your family tree.
Tree public though you may decide who can view your family tree. Free.
Free Genealogy Software for download
Free opensource genealogy software for PC and MAC :GRAMPS http://gramps-project.org/download/
Commercial Genealogy software
Most of the softwares below are free standard editions with reduced features.. A purchase is required for extra features. For example: To save or print your tree, limited number of individuals, etc.