Many people like to add words to their scrapbooks. Words help to tell the story behind the picture. There are several ways to add words to your scrapbook pages.
One way to journal is through premade words and phrases. You can find stickers, diecuts and word cutouts, all with different phrases. You can also use alphabet sets to create words on your pages. One page I did has my daughters four high school pictures, one from each year. Down the middle of the page I put the letters DPHS. In 50 years, when she looks at the page, shell know those 4 pictures were her four high school pictures.
Other folks enjoy writing in their albums. If you are going to write on the pages, choose an ink color that matches the color theme of your page. You can write directly on the pages, or you can write on paper and then attach the paper right to your scrapbook page.
How much, or how little you journal is completely up to you. In some cases, I just wanted a year attached to my pages, so that my kids would have a general idea of how old they were at the time. In other cases I wanted a city name or building name to remind me of where I took the picture. In yet other instances...