I should interject here that there will be brand spanking new history modules by the time you start. Exactly how they look is yet to be finalised, but they'll be along the broad lines of the previous set-up. We used to teach three first year modules, 1A & B on Medieval and Modern being compulsory with 1C on Scotland being optional, and four second year modules, which you had to pick at least two based (usually three) from another Medieval module, early modern, Scottish and American. The other slots were free for you to pick and choose as you please: most take politics, philosophy or economics, but English or a language were also popular. In short, the experience of current third years won't map exactly onto what you'll find. Hopefully for the better though!
New structure has a Scottish module, a medieval module, and modern Europe module and then one or two which have as yet still to be finalised covering Early Modern & America. The idea behind it is that it means all students will be exposed to the same training and thus theoretically we won't have anyone in a Nuclear Weapons course in third year having not really looked at the 20th Century since a couple of weeks in level 1B, or taking Charlemagne having not thought about the period since 1A.
There are also four Economic & Social History modules covering Britain and Europe from circa 1700 to present. It's in a different academic school so there is no requirement to take those modules, but I think they help people understand how to approach history in different ways, so I'd strongly recommend them.
Honours will be based on which staff members are around to teach: There are around 45 historians at Glasgow- one of the half dozen or so largest departments in the UK & Ireland, so at any one time eight or nine won't be around as they'll be writing books or articles. Module choice will be vast though- in some years there have been well over 50 possible module choices, of which you pick six. That's sufficiently far away that you don't have to worry about it now though.
If I'm quite honest, first and second year aren't usually what most students find interesting, the classes are broad to give everyone a little taste of everything, so it might be that you don't love it straight away, but the smaller, intensive modules on something like the European Enlightenment with intensive discussions with a professor are what the degree is built on. I'd take the first two years to find yourself and settle into university and get into good habits, and take it from there.
As an added added bonus, I won't be teaching anything this year (I was on Level 1 ESH and Level 2 American last year) as I have pressing research to do, so there is no chance that you'll run into me.
ALL students should remember there's a Scottish History library in 9 University Gardens and both Medical and Business History libraries in Lilybank House. They're not listed on the main university library search, so it might be worth checking them yourselves in case something you think is out of stock is there. Also: reading lists are designed to be instructive and not exhaustive. Glasgow's library is also one of the five biggest in the UK, so if the title on the list isn't there, I always encourage students to go look on the shelf where it should be, chances are a similar book by someone else is. The more people that read widely, the better.