You mean from Poloniex to your Steem wallet?

Click : Balances>Deposits & Withdrawals

Then type Steem (or whatever you want to transfer) in the search bar to the left or just choose it in the list.

Click Withdraw: Enter your address which in your case would be: isaac.rodebush for Steem or SBD

You don't need to enter anything for the Memo.

Enter the amount.

Double check everything and click withdraw.

Now normally it would be in your account within a few minutes but right now we don't know how long it will take.

To deposit on Bittrex ( or Polo) from your wallet you will need to do the same kind of thing in reverse (click deposit on the exchange wallet to reveal the address/memo) but make sure to note the memo - the memo is what tells them the Steem or SBD belongs to you.

For most other coins you don't need a memo - they give you a unique address but you will always need it for Steem or SBD.