09.v.12 UPDATE: There is a cheaper, non-USM version of the Canon EF 50mm f/1.8 II Camera Lens. Much cheaper but sometimes it gets stuck on the camera apparently. Yikes. Amongst those that had this problem, the general consensus seems to be spend a little more for the EF 50mm f/1.4
08.v.12 UPDATE: Another shout out for the EF 50mm f/1.4 USM over at Say Yes To Hoboken. She says that it "is gorgeous for portraits."
17.xi11 UPDATE: I received the Canon EF 100mm f/2.8L Macro IS USM as a gift. It is an amazing piece of equipment but I still need to learn to use it fully. It is very heavy but it can deliver some amazing results.
Now I am thinking about adding a EF 50mm f/1.4 USM, Standard & Medium Telephoto lens... not exactly a macro but look at this.
focal length: ≤100mm - longer means less chance of you blocking light ... or startling bugs
Top Pick This Week (barring the $$$$ Canon EF 100mm f/2.8L Macro IS USM): Tamron SP AF 90 F2.8 Di 272E
Canon EF 100mm f/2.8L Macro IS USM - $$$$ but has IS and faster autofocus than Tamron; heavier (not so good for handheld work).
Tamron SP AF 90 F2.8 Di 272E - good reviews here. Half the price of the Canon 100mm and only 10mm difference.
Sigma 70mm F/2.8 EX DG Macro Lens for Canon Digital SLR Cameras
Canon EF-S 60mm f/2.8 Macro USM Lens
EF 50mm f/2.5 Compact Macro - compact but is the focal length too short? Good as a portrait lens.
SIGMA 50mm f2.8 EX Macro 1:1 Lens for Canon SLR digital cameras
Explanations and Examples:
Macro Photography 101 at Metafilter - Jedrek suggests the EF 100 f/2.8; he also suggest this book.
Excellent explanation of macro equipment by Ken Rockwell.
Chookooloonks tells you how to choose a lens. The macro stuff is at the end.
Good ol' Wikipedia has a pretty good explanation of macro photography.
Smitten Kitchen uses Sigma 50mm f/2.8 EX DG Macro Lens. Food, miniatures ... kinda the same. This is available at Amazon. Or you can rent it at BorrowLenses.com (It only has 1:2).
Things to remember:
Ken Rockwell: This seems silly but it's very important. You need at least a foot or so between your lens and the subject so you don't block your light or scare your subject. You usually want the longest macro lens you can afford.
Chookooloonks: The smaller the aperture number, the more desirable the lens generally is, and therefore it will be priced accordingly. My general rule is that you should always buy a lens with the smallest aperture number you can afford.
Magnification matters. I need 1:1 (not available with the 50mm but available with the 60mm).
Working or Focussing (thank you Renatta!) distance is how close you can get to your subject (e.g., 90mm)