Find a chart - a good old fashioned paper chart. Here is one from the National Archives:
Print it out and using your pencil, enter your name, date and place of birth, date of marriage. Enter the name of the document you used to confirm the information (memory doesn't count). Your birth certificate and marriage certificate. Here's an example:
Surname, First Name, Middle Names, Date and Place of Birth, Certificate Name and Number
Doe, Jane, Francis, 29 October 1973, Hamilton ON, Province of Ontario, Registration of Birth 0004321
Then add in the same information for your spouse and any children you have. Include the documentation that you used to confirm the details.
Now it is time to start working backwards. Fill in the same information for your parents and your spouse's parents. Fill in any of siblings of yourself or your spouse - the children of your parents and parents-in-law. Again, fill in all of the details from the documents that you used to confirm the information that you have added into your charts.
Next move back to your grandparents, filling in all of the details for them and their children. Again, make sure you document the details of the records you used to confirm your information.
Finally, move back one final generation to your great grandparents. Add all of the details on their births, marriages, children, and marriages for the children, dates of death, etc. Remember to cite your sources. The details of the documents that you used to verify the information.
If you are speaking to relatives to ask their dates of birth and marriage, don't be shy about asking for a copy of the certificates so that you can use them to verify the information. Explain WHY you want the document, so that the person knows you aren't going to use the information inappropriately.
Once you have these 5 generations (your children, yourself, your parents, your grandparents and your great grandparents), you are ready to buy a family tree software program to add the information to your computer. This will give you loads of room for expansion. Don't forget to add the details of the documents in the software program. Usually there is a space for this called source citation.
The icon may look similar to this:
Happy tree building.