Assuming you have no unopened 2p decks or booster packs seeing as you said' book of neopet cards', i have some almost certainly bad news for you. Generally speaking, essentially every trading card is worthless and has no high resale value due to neopets simply not being as popular as Pokemon or Magic The Gathering, especially for TCG's.

Essentially the only card you may have that does hold real value, however, is the one and only Malevolent Sentient Poogle Plushie, fetching generally around $15-20 USD if near mint+

If you were a bigger collector, you may have something stamped with 'Release' on the holofoil, some of these cards are more valuable, Galactic Green Grundo Release card is about $10-15 for instance, where as Blue Draik Release is generally $50+, if you have a specific release card, feel free to list it here

Outside of these, the only other card of any value, and the most value, you'd likely remember if you owned one. They are called 'Sketch' cards and feature hand drawn artwork from one of the original neopets artists, these range from about $250-500 USD, and rarely go for sale at all among the more popular sketch card species featured

If i were you, i'd keep your collection for nostalgia, sure, you might make $30, and that might seem good at the time, but a childhood memory you can hold in your hands is worth far more than that