What sort of money did they use, and how much was it worth?

From the middle of the eighth century, Anglo-Saxon coinage standardized on the silver penny, which was about the size of (though much thinner than) a modern quarter or 10p piece. For designs, the coins tended to have the king's head (with his name around the rim) on the front ("heads", or obverse) side, and a pattern (often a cross) with the moneyer's name around the rim on the back ("tails", or reverse) side. The Northumbrians didn't switch to the new standard and continued to issue base silver coins (eventually base copper coins) until the independent kingdom of Northumbria was snuffed out by Vikings in 867. Everyone else, however, used silver pennies to the end of the Anglo-Saxon period. There are references to "shillings" and "pounds", but both seem to be set amounts of money, made up in pence, rather than separate coin denominations. A further unit, which hasn't survived into modern times, the "mancus", was worth thirty pennies, and it has been suggested that a handful of later gold coins, with the same designs as silver pennies but three times the weight, are actual mancus coins. Since only four survive from the whole period, it's hard to say what role they played. As for ha'pennies and farthings, these were made informally in the tenth and eleventh centuries by cutting an existing penny into halves or quarters.

So what could you buy with a handful of silver pennies? The short answer is that we don't know, but from a handful of clues a penny seems to have been a substantial sum of money, more equivalent to a ten or twenty pound note (C$20-50) today. An eleventh-century law of Cnut (II Cnut 24) notes that witnesses are to be present for any monetary transaction involving four or more pennies (this was an anti-theft provision so that there would be witnesses as to who owned what later: if the threshold for the law to take notice is set at "four pennies", a penny is clearly a tidy sum). A tenth-century law (VI Æthelstan 6) notes that a horse could be valued at up to half a pound (120 pence), an ox at a mancus (30 pence), a cow at 20 pence, a pig at 10 pence, and a sheep at a shilling (here perhaps 4 pence). Another code (Dunsæte) gives quite similar numbers, adding that you could get a goat for two pennies. While other codes list fines for offences and injuries, and other documents note monetary payments for estates, they bring us no closer to answering what a penny could buy in our own modern-day terms.