If possible it is important to decide if you are going to do a “Direct Line” tree or an “Extended Family Tree” before you begin working on your tree. The “Direct Line” would be your parents, their parents, and then their parents etc, going back as far as possible. You would not include any siblings of any of your Ancestors. This is probably the easiest and most time efficient way to begin. Otherwise it can get confusing and overwhelming really quickly. You can always go back at another time and add in all those other people a little at a time. This also gives you the chance to discover for yourself how you can best organize your pictures and documentation. I recommend that you begin with the “Direct Line Family” because it will be easier to add the “Extended Family”.
Some people prefer to do all the “Extended Family” in the beginning. Or it is possible that you have already been working on your tree and started it this way. If you think you can handle it, by all means do it. Just remember that you will probably be adding hundreds of people to each generation right from the start. In my case, this is how I did it. I didn’t think about how I wanted to add people, I just started doing it and it quickly got away from me. My Father had 10 brothers and sisters. Each of them had spouses and many of them had numerous children. If you do the math you see how the tree expanded rapidly. The farther back you go to your earliest Ancestors you will find that most of those families were large. When including everyone it is easy to get side tracked adding in people who are not really directly related to you. In working on my first “Extended Family Tree” I found that I have added a “nephew of the wife of the cousin of the husband of my 3rd cousin” in one family line. I had to waste a lot of time going through the trees making numerous corrections. I eventually stopped adding everyone and concentrated on the “Direct Line” then I went back and “filled in the blanks”.