I just made my first (receiving) transaction with electrum v. 2.6.4.
From the history tab, right click on the only transaction, click details. I see 2 inner windows: Inputs 1, Outputs 8.
The input address i guess is where the btc i received came from. The output addresses why are they 8? One of them, the second one is marked green and is my receiving address with the correct btc amount i received. The other 7 what are they?
They all have various btc amounts and are unrelated to me.
Who ever sent you coins also sent coins to other addresses in that same transaction too, it is normal to do that to save the transaction fee. You can also do that, if you want to send coins to different addresses in a single transaction, go to "Tools>Pay to many" and you can add as many addresses you want there.
The format to follow is this; "Address, Amount"
For example:
1abcdefgh, 0.001
1Someone, 0.01
Etc.