Resignation announcement is an oral or written statement that one is resigning a job position. Written form is mostly done through resignation letter.
Many companies don't like to keep the employees as soon as they have submitted the resignation announcement. And some companies would react critically to your decision, while some will try convincing you to stay. So, check out through your colleagues about the resignation policy of your company.
If your severance pay, unemployment benefits, stock options, and all other kinds of compensation are there, you should not forget to take it as you serve the resignation notice.
Better prepare in advance for resignation, becouse many companies won't allow access to their operations area, your computer, your files, your email etc once you put your papers. So, make sure to clean up any objectionable personal stuff fro your desk or computer before you resign, else the employer may find a reason to block your compensation.
And don't tell your employer that the another company has offered you better pay package and you may continue to work if a counter offer is given. It's unprofessional. There are a few chances that your employer will negotiate for a better salary for you, but the implications of your action will show your disloyal to the company. Majority of employees who accept the counter offers are either voluntarily leaving or being dismissed by the company after around 6 months. This is purely because of the question on your accountability to the company.