My main interest is in predecimal silver coins from Victoria forward - florins and half crowns in particular. I love the ornate designs on the reverse, and they remind me of my childhood in England. Back then, you could actually buy something for "two and six," as we used to say. I don't have much interest in post-1970 coins, but will occasionally buy a set from the Royal Mint just to see what they look like.
I appreciate the suggestions on reference books. When I first started this venture I bought a copy of Coincraft's 1999 Standard Catalogue of English and UK Coins - 1066 to Date, if anyone remembers that from nearly 20 years ago. It's helpful in identifying types and designs, but the comments on grading and values are almost worthless at this point due to the passage of time. So I've ordered the grading book Peckris suggested.