But it certainly doesn't have to be like this. When starting out the best approach is to take small steps. Join just one site -- preferably Twitter. Just keep chipping away at it. Tweet, engage, reply, retweet and follow a few people a day and before you know it you'll have several hundred quality followers. If you log in daily for ten minutes or so you really can absorb this into your daily ritual without noticing.
After several weeks of this you'll really start to understand why it can be so beneficial. You will have connected with many good people in your niche, and had some interesting, albeit brief, conversations with them. You will certainly have drawn a few new visitors to your site, too.
I know that social media is not for everyone, but odds are that you will have caught the social media bug by now. You can then start to build followings on the other big sites. You won't be a beginner anymore so the process will be much quicker.
Repeated use of such sites also really speeds up your ability to process information. It's quite amazing how much you can get through in a few minutes. Before you know it you'll be engaging thoroughly on several networks in the time it took you to do this on just one of them before.
While regular participation on several big social networks isn't crucial, it is highly beneficial -- not least because you can engage in cross promotion and therefore build followings on each network a bit quicker.
If you need to streamline the process even more, there are some excellent social media management tools available such as Hoot Suite that enable you to update several accounts from the one dashboard, among other things.