Collect all the information you can NOW.
Visit your Grandparents, Great Grandparents, Aunties, Uncles and any other family members now before it is too late. Once they are gone (or their minds have gone on holidays) then so much information and knowledge is lost forever.
Collect all the information that you can and copy photos. Record discussions if possible. Getting family members to look through old photos is a great way to get them reminiscing and telling stories about the past. Ask lots of open questions (ie questions where the response is detailed rather than yes or no - begin with What, Where, When, Why, How) to prompt them to expand.
One of my biggest regrets is that I did not talk to my grandmother more about her family and upbringing. I had plenty of opportunity as she lived to age 96. Unfortunately Family History wasn't as important to me then and I always thought there would be more time.
After Gran died, it was discovered that she had albums of photos dating back to the early 1900s. She was a keen photographer. I was so fortunate that my Aunty saved them from going to the tip. However when I look through them now, I would love to be able to go back in time and talk to Gran about them.
I now make a point of visiting family members, working from oldest to youngest. It is also a great opportunity to travel around the country and see places I haven't been before.
The photo above, taken in 1933, is of my grandmothers first flight. It cost her 7/6 for 10 minutes. I always thought Gran was so old fashioned but looking through her photo albums I have learned a different side of her. I would have loved to hear her tell me all about her first flight experience.
My tip: Don't delay. Collect as much information as you can now before it is too late.