I have four Canon Zoom Lenses currently used on two digital EOS bodies, but I have also bought a couple of others which have quickly gone back on ebay.
If you have a compatible efs body 300D etc, the standard EFS 18-553.5-5.6 zoom lens works pretty well. Its light and easy to use and very inexpensive on ebay at around £35. I have also owned an EF 28-90 f4-5.6 lens and an EF 55-2004.5-5.6 lens in this range (same styling and spec) with pleasing results, if you can find a cheap one go for it but Canons mid range lenses are generally found for not a lot more on ebay and when it comes to performance there is no contest. Both lenses are great if your budget is tight and are ideal to accompany the 300d etc as an inexpensive partnership to take abroad as a holiday/snap shot set up.
Stepping up a notch (or several) on both image and build quality, look out for theEF 28-105 f3.5-4.5 II USM lens (not to be confused with the cheaper consumer f4-5.6 lens), with glass elements, its markedly heavier and chunkier but feels great in the hand. This and the following two lenses offer full time manual focusing even when switched to auto without damage to the lens. Again on a digital body with a 1.6X multiplier it makes a useful standard to mid zoom. Special effects filters work well as the front element on this and the following lenses does not rotate. Examples can be won at around £70-100 and are definitely the best bargain out there.
My everyday lens is a EF 28-135 3.5-5.6 IS(FANTASTIC). With image stabilizing you gain the equivalent of two extra stops, which means hand holding in low light is a sYnch (but very heavy on battery use). With four active kids I became the unofficial school sports photographer at cross country and athletic meetings (indoor and outside). At f3.5-5.6 it is fast enough for most events and focusing has always been quick, silent and accurate. Again it is a dream to hold and balances my 20d+battery grip perfectly. The Macro function is also pretty good. A bit more expensive to find a good one but well worth the search. This is a lens that I now regret selling.
I now own three L lenses EF 17-40 f4L , EF 24-105 f4 and an EF 70-200 f4L lens, for when out and out quality is needed. These lenses are capable of producing fantastic images and with huge magnification that still delivers crisp full detailed prints. When I need to present images, much of my photography is general architecture and city scape plus close quarter images of building materials my 17-40 L is the lens of choice.
WHAT NOT TO BUY
EF 100-300 f4.5-5.6. Cheap for a Canon lens at £99 on ebay, but impossible to hand hold on a digital 1.6x body when used at the longer end of its range. This lens hunts like crazy when focusing in anything but the mid day sun during June to August and unless you really have the need for this lens avoid it like the plague. A cropped image off of any of the lenses mentioned above possibly even the lowly EFS 18-55 could produce a clearer sharper image.
EF 55-200 f4.5 Reasonable lens if your budget is limited but the quality is not great on both image and build and again this lens will hunt when focusing if being used in anything but the best lighting conditions. It is also noisy in use and creeps (actually scampers) when slung around the neck (front element also rotates which is annoying if you are using effects filters). For approx the same money an EF 28-105 f3.5 lens can be bought giving better results that will stand cropping and will focus quickly, accurately and quietly when needed to catch that moment.
USM Focusing (Ultra Sonic Motor) is Canons brilliant quick and quiet ring motor focusing system.
EF lenses can be used on both digital and film SLR's
EFS Lenses have the rear element sitting inside the body and closer to the sensor. These lenses are body specific so check compatability.
f rating- the lower the number the lower the light conditions in which the lens will perform.
L series lenses are the highest quality of glass and construction. (Most are water resistant designed for professionals)
Use a good coated filter and lens hood to protect the front element and to reduce unwanted stray light and glare. Most of my lens hoods and filters have been bough via ebay auction or ebay dealers.
Visit Canons web page to check out the specs and dedicated lens hoods
Thousands of people have read this guide so please dont' forget to press the YES button if you have found any of it helpful. Thank you.