Here are the practical info, and everything you need to know, to drive in Sweden without problems.
As always, it is recommended to follow some basic and universal rules.
Always respect speed limits. Avoid driving if you have drunk: the permitted alcohol limit is 0.02%.

In the event of an offense, foreign citizens can pay the fines on the spot. Alternatively, you can go to the bank within 3 weeks.

BASIC RULES TO DRIVE IN SWEDEN

In Sweden you drive to the right and overtake on the left. Remember to always respect the safety distance.
It is always necessary to give priority to pedestrians who cross or are about to cross a road; even if there are no pedestrian crossings on the ground.

In the event of an accident, YOU MUST ALWAYS STOP and provide assistance; it is important, however, not to hinder circulation. Pay the utmost attention to the signs of Danger: it is not uncommon to come across on the roads with animals.

DOCUMENTS TO DRIVE IN SWEDEN

Driving license, registration certificate and valid insurance certificate. If you are driving a vehicle that is not your own, we recommend that you take a DELEGATION TO CONDUCT. This is a delegation of the vehicle owner with an authenticated signature. It is not mandatory.

VEHICLE EQUIPMENT

The seat belts must be fastened to all seats, front and back (if any).
By car it is mandatory to use a triangle. From December to March, winter tires must be fitted on the cars.
The dipped headlights must always be switched on, both day and night.

ROADS AND SIGNS

The motorway network has undergone a marked improvement only since the end of the 90 years. The modernization process has led to the expansion of the network.
The motorway, or Motorväg, is identified by the letter E followed by a number, and a green background signal. To drive in Sweden from North to South, there is the E4, with an extension of over 1500 kilometers.

There are also some sort of semi-motorways, the so-called Motortrafikleder. They are almost similar to the Motorväg.

In Sweden, the motorways are all free. Tolling is only foreseen by covering some specific points. More info from here.

You can drive in Sweden along the motorways Riksväg and Länsväg.
The first ones are Swedish national roads. The Länsväg, on the other hand, are city streets, subdivided into primary, secondary and tertiary, depending on their importance. They are identified only by a progressive number.