Advices for House/Appartment rental?

Hello,
We move very soon to Sweden with my family (4 peoples). We have to find an appartment or a house before mid-july. Do you have some advices to give me? Which process to adopt to be efficient?
- Web sites ? which one?
- Agency ? which one?
- Appartment/House hunter?

Where it is easier to find something?
Thank you for your experience sharing.
Regards,
Sébastien

Finding an apartment to rent is not that difficult if you are willing to take a second hand contract. But first hand....well is another story. You have to wait for years until your chance comes. Long story short, look into blocket.se and good luck.