First time bitcoin buyer; been reading, but still not sure how to purchase
The long alphanumeric address is one of your pseudonymous representations in the Bitcoin network. You may hand it out to your business partner in order to specify where you wish to receive the money.

After you've imparted your address, the sender may create a transaction which is a message to the Bitcoin network that signals his intent to sign over some of his bitcoins to you. This transaction will then be propagated through the network and hopefully incorporated into a block for confirmation. Once the transaction is written to a block, it has become part of the blockchain and the sent amount has been —bar exceptional occurrences— reliably signed over to your wallet.

Since there was really only one piece of information or step missing from your description, I hope that you're well informed at this point. ;)

To get a better overview on some related topics, may I suggest the following topics:


What&#39;s the difference between a wallet and an address?
Can someone explain how the Bitcoin Blockchain works?
I am new to Bitcoin, how can I get started?