First off, I guess Guinevere is a maid? Which is sort of weird? Since she's Guinevere? And it seems like she loves Merlin? Which is also weird? Since she's Guinevere?
And, until I just wiki'd a second ago, I was under the impression that Morgana (I spent the first half hour of the first episode I watched going 'someone call her by name, dammit, I don't know who she's supposed to be!') was married to Uther, but apparently she's actually his ward. I had sound reasoning for why I assumed they were married, but apparently my detective skills are off. I suppose her being a ward makes it less icky if she and Arthur get together, as opposed to them being related.
Other than those two things, I followed the rest of the characters easily enough. I enjoyed all the actors, though Merlin's character is slightly bland to me at this point. I think I want a bit more mischievous Merlin, but maybe that will come later on. He did spend most of the second episode I saw in a coma, so that's not the best time to judge. I especially enjoy Bradley James as Arthur, who manages to do a really great combination of benevolence, arrogance, enthusiasm and eye smouldering. Plus, I could listen to Anthony Head talk all day.
So, I shall continue to watch and hopefully I'll be able to find the first two episodes somewhere before long. Arthurian stories are always fun since there are so many different interpretations of it. Not to mention spellings and pronounciations of characters' names.