Despite being set in the fictional lands of Westeros and Essos, A Clash of Kings is noticeably lacking in the thous and forsooths that make old-school poetry such a pain for contemporary readers.
Martin's descriptions are easy to follow, and his characters speak in a way that somehow feels like they belong in a medieval play and modern-day political drama simultaneously. You may have to look up words like portcullis or gorget since you likely don't have either lying around your house. But, hey, that's what dictionaries are for.
The difficulty here is trying to remember who everybody is. Sometimes you can feel like Costello in the famous Abbott and Costello routine, "Who's on First," only instead of fielding a baseball team with players sporting crazy names, Martin is populating an entire world with people that have some really crazy names. Looking at you, Xaro Xhoan Daxos.
Thankfully, the Internet is full of fan sites that can help you keep track of the whos, whats, and I don't knows of Martin's world. With a helpful tour guide a mere Google search away, even the most timid readers of contemporary fantasy will find a trek through Martin's world pretty easy-going.