What lenses do I buy?

[Sodigital]

I want to start shooting macro but don't know what lense to start with.
I notice that a lot of you have EF 100 f2.8, is this the one I need?

[Dragonslayer]

To be honest get the lens with the most reach you can afford, the Sigma, and Tamrons are excellent lenses and I would put them up against canon at least on optics, The canon lens will most likely be better sealed and will report distance info to the camera I know Sigma doesn't and not sure about Tamrons lenses on that. I have the 180mm and it's as sharp as canons 180 is. The more reach the better as it allows you a buffer zone when shooting as some subjects will not tolerate close approach.