The traditional route would start with a 3-year BSc. You automatically get a BSc (Hons) as long as you get a third class classification or above - there isn't a separate Honours degree. You would then go onto doing a one year MSc degree. However, a lot of universities now offer 4-year MSci degrees (note that they're MSci, not MSc) which essentially act as a BSc and an MSc - the last year normally has a research component and basically acts as a precursor to doing the PhD. You'd then apply for a PhD and hopefully get a placement. I'm not entirely sure what you'd do after that, but that's a long way away so you don't need to worry about that at the moment!
Another slightly confusing thing is the terminology, because there are a lot of different titles for the same thing. A BSc is a 3 year undergraduate degree and an MSc is a one year taught or research based postgraduate degree. An MSci is a 4-year integrated masters undergraduate degree, but universities sometimes give the MSci a different name. For instance, some universities call their 4-year integrated masters chemistry courses MChem and the same thing goes for MPhys. I'm not 100% sure what the MPhil is, but it appears to be similar to a research-based MSc - it is definitely not the same thing as an MSci.
It's really confusing, I know. The first decision you need to make is whether to go for a 3 year or 4 year undergraduate degree. MSci degrees appear to be very popular at the moment so if you're certain you want to go into research, it seems like the way to go. Given that you're in Year 11 at the moment, I really don't think you need to worry about post-masters right now!
But essentially, the two main routes are:
BSc -> MSc -> PhD -> Job
MSci (or equivalent) -> PhD -> Job