Anyone who is anyone is Tweeting on Twitter. The mini-messaging service is now mainstream and packed full of interesting people and celebrities to "follow" and receive updates on what they're saying and doing.

But it's also packed full of not-so interesting people and celebrities to avoid too.

So read on to brush up your knowledge on how to find the best people among the millions of users out there in the Twittersphere.

Friends – As low-tech as this sounds, the easiest way to find a friend's Twitter account is to ask them for their username.

But the Twitter search box should also be your starting point. You'll find it in the right hand column of your own Profile page.

If you don't have an account yet, read how to sign-up in our handy intro guide. Just click the link on the top left.

Mutual friends already on Twitter are also a good place to look for mates. Check that person's list of friends and simply "follow" who takes your fancy.

You can also use http://search.twitter.com, a slightly more powerful tool, which will detect far more mentions of the person you are looking for – whether it's their real name or Twitter username.

Celebrities & Public Figures - Many well-known personalities and other public figures have discovered the benefits of Twitter. Many mention their Twitter account name when they're on TV or the radio, in print in newspapers and magazines or they post it on their website.

But it is very important to ensure you follow the "real" celebrity and not someone pretending to be them. So if searching via the web, be careful to make sure the information comes from a reliable source otherwise you could leave yourself open to hackers.

Many cybercriminals spoof celebrity accounts by creating fake ones and then post links on it, which they encourage people to click. These can be dangerous though and infect your PC, leaving your machine with a virus.

Celebrity Tweet - http://www.celebritytweet.com/ - is one good way of finding showbiz types as well as following Twitter feeds from the media such as Heat magazine (@heatworld), The Sun's Bizarre column (@TheSun_Bizarre) and the Mirror's 3am Girls (@3am).

There is one simple way to check whether a celebrity is real or not on Twitter and that is whether their account is "verified". You'll see this in their profile information. But not every real celeb will be verified as it takes a while to apply for so if in doubt, leave them out.

Interesting People - Perhaps you're not looking for specific people but rather a type of person who has similar interests to you or to other people you already follow.

One way to find these is to look through the contact lists of people you already follow until you find accounts that look interesting. Also check out the profiles of people your followers tweet about and if you like the look of them, add the accounts to your list. The more people you follow, the more you'll get out of Twitter, that's the whole point.

You can also use a service like Mr Tweet - http://mrtweet.com/ - which describes itself as "Your Personal Networking Assistant". It recommends new Twitter users based on those you already follow by trawling through the site and matching up comments.

Trending topics are also a good way to find people who have the same tastes and interests as you. See what topics are hot from the list, and scroll through the tweets and then select a few of the users discussing it who you agree with.

Twitter desktop and mobile applications such as TweetDeck will also come up with recommendations for you, based on what you tweet about and who you already follow.