If your intention is to play together, you can't have 2 users on the same account with different names and whatnot, it's just not possible. The general rule of thumbs is 1 person = 1 account.
I'm pretty sure that you can use two different accounts on one computer, but not play on them at the same time, and you'll need to purchase a second account. Also, since the default save location (on Windows) is "C:\Users\Name\AppData\Roaming\.minecraft" this means that your Minecraft profiles will also be separate unless you have a single user account on the computer; if the latter, you should make separate profiles (I believe it already defaults to your IGN, though I haven't reinstalled it since 1.6 added multiple profiles) with separate game directories for your worlds.
Note that it is also possible for two people to use one account (as noted above with two user accounts on one computer the .minecraft folders will be separate) but you won't be able to use a custom name or skin; these can be changed, but only once every 30 days for names, and a second account is much more preferable, plus the combined costs of two accounts is still less than what you might pay for many other games.
My wife wants to pay too, I was wondering since we only have one computer is there a way to start a second profile on my account?
If you talking about adding a different profile to the launcher, then:
Open the launcher, click "New Profile" at the bottom left.
Change the name to whatever you want, also change the version to.
My Website
If your intention is to play together, you can't have 2 users on the same account with different names and whatnot, it's just not possible. The general rule of thumbs is 1 person = 1 account.
I'm pretty sure that you can use two different accounts on one computer, but not play on them at the same time, and you'll need to purchase a second account. Also, since the default save location (on Windows) is "C:\Users\Name\AppData\Roaming\.minecraft" this means that your Minecraft profiles will also be separate unless you have a single user account on the computer; if the latter, you should make separate profiles (I believe it already defaults to your IGN, though I haven't reinstalled it since 1.6 added multiple profiles) with separate game directories for your worlds.
Note that it is also possible for two people to use one account (as noted above with two user accounts on one computer the .minecraft folders will be separate) but you won't be able to use a custom name or skin; these can be changed, but only once every 30 days for names, and a second account is much more preferable, plus the combined costs of two accounts is still less than what you might pay for many other games.
TheMasterCaver's First World - possibly the most caved-out world in Minecraft history - includes world download.
TheMasterCaver's World - my own version of Minecraft largely based on my views of how the game should have evolved since 1.6.4.
Why do I still play in 1.6.4?