I have recently purchased a Canon 5D Mark II, which is quite a step up from my previous 450D. I am hoping to purchase some lenses that would be most versatile primarily for travelling photography (Europe), keeping in mind I will be carrying them with me everywhere I go. I am hoping to purchase 2 (3 at the most) lenses, that are middle of the range in cost (I'm not a professional). I'm hoping I could get some suggestions on what 2-3 lenses individuals would pick if in my circumstance. And any thoughts on whether I should consider lenses from the Sigma range.
I am also hoping to purchase a suitable flash. I have never had the need to purchase a flash before so I have no idea where to start. I don't expect I will need to use this very often however would like the option available when required. Any advice on purchasing a flash would also be appreciated. Thanks in advance.