A fundamental thing which a potential expatriate who wants a job in Saudi Arabia should know is the salary structure here. Please note that there are three different salary scales in almost all companies, depending on your nationality. The highest salaries are invariably for Saudi nationals. Next come citizens of the US, UK, South Africa, Australia and EU. The least salaries are for people from the Indian subcontinent and the Phillipines, collectively known here as "Eastern expatriates".
You may be quite surprised to learn that the job may be the same, but will find a guy from another nationality earning far less or far more than you. Also, you must be prepared, particularly if you are going to work in a government organization, that all higher level positions are invariably occupied by Saudi nationals. The only exception may be for the private sector, but here too the top boss will definitely be a Saudi national.
It is also quite common here that people with far lesser qualifications and experience may be your boss, but you should be mentally prepared for this too. Remember, as mentioned in my earlier post, if you are already in a senior position in your home country, you must definitely bargain your salary / position well and make things amply clear with your potential employer. Make sure to have all your emoluments / benefits in black and white in your contract, so that there is no heart-burn once you arrive in the kingdom.