In your Facebook profile, click on Create -> Page (as marked in the picture), or click on the link below:
If you would like to create a Facebook page for your business, choose the first option. Click on the “Get Started” button.
Type in the name of your company, and choose its main profile from the list.
Upload a profile picture. (Use a square picture, preferably your logo.)
The profile picture is displayed in 170×170 pixels on computers, in 128×128 pixels on smartphones, and in 36×36 pixels on traditional mobile phones.
If you have a business logo in good quality that can express the essence of your business, or is already well-known, we suggest you to use this as your profile picture.
After uploading your profile picture, we suggest you to also upload a cover photo to your Facebook Business page.
The cover photo is displayed in 820 pixels width and 312 pixels height on computers, in 640 pixels width and 360 pixels height on smartphones.
In terms of size, 851 pixels width and 315 pixels height is the best choice for your cover photo or video.
When the cover photo is uploaded, your page is ready to be used.
For further settings, you can find a detailed, illustrated guide in the following post: