I'm trying to deploy my contracts with Remix to Ropsten, but I don't know how to do it. Can you help me? (I have a ERC20 token contract, and a CrowdSale contract)
You can simply deploy them as separate contracts.
On the "DEPLOY & RUN TRANSACTIONS" section of Remix, you can choose which contract you want to deploy, even if they are in the same file.
When you have chosen your contract, simply hit "Deploy" on that same page.
You can choose your network by specifying the "Environment" (on that same page) and choosing "Injected Web3".