I've been mining eth for a little while now and I've got .4 eth in my address. I want to be sure that I remember my password and validate that the eth is in my wallet on my computer. The thing is I don't know where or how to validate my password using geth or how to see how much if any eth is actually stored in my wallet on my computer. Any ideas? Thanks.
To see how much ether you have, you can use a public scanner such as https://etherscan.io/address/(your_address), or you can sync your Geth and in the console type
To check if you have the correct private key, you can again try
personal.unlockAccount((your_address)), or you can use MEW either online or offline to show your wallet information. If you can unlock your account and it shows the same address, you have the correct private key.