Here is a primer I created a while back
. I have used coinbase in the past. I would recommend that you always keep it on your person because just like gold and silver if you dont hold it you dont own it
That being said if you want to use some for transactions and purchasing then you will have to leave some out and about on the web. I would recommend using two factor authentication for sure. I have used the blockchain.info API and I liked it so thats a decent site. I go over some wallets in the primer vid 1 and 2.
You should always back up your wallet.dat file. Keep it on multiple usb sticks and in separate locations for safety and loss reasons. That is your bank account so you wouldnt want it being lost if its inaccessible anymore.
You can also print out btc onto paper now. There are many YT vids on that and I have friend who has a lot of BTC and he has done that at this house. He swears by it and loves it. Technically if you can remember the really long number and or write it down thats all you need to logon to anywhere in the world and get that money all back.