Genealogy can take on many forms and have a variety of effects on different people. It can be exciting when you find an ancestor you've been search years to find. It can also be frustrating when you know your ancestor is in the census records but they claim different.
Even if you don't think you have that many relatives, say your family was small, don't think that you won't find anything interesting. Even a family that had one or two children can lead to ancestors that had 10 or 12 who had children and well you know how it goes from there. That's the other reason collateral genealogy is so important, because you never know what you'll find out about great-grandpa if you don't dig into information about his siblings, aunts and uncles.
Yesterday, I wanted to find a photo to put on Facebook. Its of my brother (13 years my senior) holding me a few days after I was born. It was taken in front of the Christmas tree and its always been a favorite. I cleaned out the closet in the room I use for an 'office' but haven't found it yet. The room itself has its own history in that it was once my brother's bedroom, before I came along anyway. Then it was my room, once he moved to the room upstairs. Then it was my mother's room for a while. After she passed away and I finally broke down and went through her things, I decided to turn it into an office.
Its been an office where I keep my computer, my genealogy information and for at least a part of it, my Nancy Drew and series book collection. It has my computer desk, a desk my paternal grandfather refinished that holds office supplies, a day bed (that my cat loves to sleep on and under), a bookcase that holds some genealogy and some series books along with a stereo and a 5-shelf bookcase that has most of my paperback series book collection. But the closet, at least until yesterday, had mostly junk in it. It is just right for a genealogist who is accumulating a LOT of paper and let's face it, even though you do most of your research using a computer (or at least I do) and put what you find in a computer program, you are STILL going to collect information on paper, especially when you print things out.
I know you're thinking, what's your point? My point is that even if your family is small now, it probably wasn't this small 100 or even 200 years ago and if you have been thinking about starting to research your family, be prepared to collect lots of information. Even if you don't think you will, BELIEVE ME you will. You can start out using part of a room but if you have the space, like an extra room in your house, take advantage of it and make that your genealogy room. Granted I have split my office between genealogy and Nancy Drew but don't think the teenage sleuth takes up more room than my ancestors, she doesn't.
You may start out with just your four grandparents but remember that they EACH had two parents. One other thing, have FUN doing the research I think that's the most important thing you can gain from starting, even if you only do it on weekends or when the kids are asleep. Remember, you can always search online in your PJs at 3 am. :-)