You will do 95% of your pictures with the 18-55mm lens.
You could do the remaining 5% with the 55-250mm lens.
Many people who were raised on a point-n-shoot camera are accustom to having only one lens and tend to drift toward a lens that does it all.
But such a lens is usually twice as heavy as the 18-55mm lens, and such a full range lens tends to be not as good optically, plus it costs about the same as the other two lenses (combined) that I mentioned
The 18-135 lens happens to be one of those that is not rated as well optically.
Here is a link to Canon lenses:
http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup
If you want to see a review on specific lenses here is a European site that does a good job on lens reviews:
http://photozone.de/Reviews/canon-eos
...
I've been doing some research and have finally decided to purchase a Canon T3i as my first DSLR. However, I'm still debating on the lens to get. Should I go for the regular EF-S 18-55mm f/3.5-5.6 IS II lens, upgrade to the EF-S 18-135mm f/3.5-5.6 IS lens, or get the 18-55 plus a EF-S 55-250mm f/4.0-5.6 IS lens? As I mentioned, I'm new to SLR photography, having used point-and-shoot cameras mostly. I'm planning on using the camera for vacation pictures and regular family pictures. Any suggestions?

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