Hi Maniic!
No problem
.... I'm not always the fastest in replying either .... and I travel a lot, so that makes it sometimes a challenge.
Photography is just a hobby, have been active with it on and off for years now ... my dad is to blame haha.
I would indeed assume than when an EFS lens says "10" then it means really "10".
As for recommending a lens: that's hard!
I love my big lens, I mean absolutely love the quality (Canon EF 70-200 f/2.8 USM), but it's expensive, not suitable for close by, heavy, and BIG.
I guess I most often use the Canon EFS 18-135, which came with my camera.
With my previous Canon I had the Canon EF 28-135, great lens, and I regret selling it with the old camera. Also, this is NOT an EFS so multiply by 1.6. Great glass though!
I also have the EFS 10-22, which is not a bad lens, but the aberration at the edges is a little disappointing.
I do have a Canon EF 50, great quality but no zoom and in the end I never use this one.
If possible in your region, consider renting a lens before buying. I have done this once (for the L lens) and right away had a good impression of what to expect.
For no logical reason I have always stayed away from non-Canon lenses, but that doesn't mean that those are bad in anyway. Like I said: for no logical reason ...
I definitely recommend to checkout DPReview for their lens reviews and their forum. There are quite a few folks there willing to help out selecting a lens. I also recommend to always check the comments at Amazon.
Now that I have you confused even more ... haha