A few points to remember

1. Apex is a case-insensitive language.
2. The New, Edit, and Delete options of Apex classes are not available in the production organization.
3. As a best practice, start class names with an uppercase letter and method names with a lowercase letter.
4. When deploying using a change set, it runs all the tests of Apex code. If you have low code coverage, you will not be able to deploy it and it will fail every time; however, with Force.com IDE, you can push code without coverage.
5. The blob data type represented as binary data is stored in a single object.
6. If you want to execute code repeatedly, use do...while, while, or for loops.
7. Rolling back transactions is also supported by Apex.