I recently got the Canon EF-S 55-250mm IS II lens as a complement to my 18-55mm kit lens for my 550D. I was looking for some advice\best practices for using a telephoto zoom, any associated accessories like hoods that would be useful and any gotchas that I should watch out for. My intended usage for the lens is to shoot stage shows and portraits.
I found a similar query for Point & Shoot cameras
I decided to buy this lens based on the advice to an earlier question I had asked. The lens is fairly light for a telephoto zoom (~400g), and not too large either. However, it is considerably longer than the kit lens. One of the main reasons I picked up this lens was to understand the longer focal lengths better without investing in a high end lens right away (photography is a hobby).
The 70-200mm f4 L IS was one lens I did consider, but that was in a different league - both in terms of price\quality and size\weight. I wish to explore the longer focal lengths before I make serious investments on pro quality lenses - zooms or primes.