Well, most likely your fist thought is that "Is Iran enough safe for me to go?". The answer is yes and the proof is as simple as a Google search for topics such as crime in Iran against foreigners,...etc. But irrespective of goggling!, Iran is really safe and especially for foreigners. Iranians perceive foreigner tourists are absolute guests. they would go out of their way to make sure you feel at home.
Saying that ,we don't want to say that Iran is absolutely safe. you always need to take moderate caution in keeping your possessions in safe places. Hotel safes are the best for Passport, money...etc. Do not try to carry around your camera wherever unnecessary. Carry limited amount of cash with you , when you go for daily walks .
Do not try to visit totally remove areas on your own, It is totally logical to hire a guide or driver to take you wherever you wanted to go ,if it is way out of a town.
If you are traveling with you car or bike, you might want to make sure you are getting a hotel that has sufficient parking place and of course obviously safe.
Police are omnipresent , but importantly ordinary people would rush to your help if you really need to ask them. Komak is the Iranian world for help. if somebody annoys you , all what you need is to go to the closest shop next to you and tell the shop owner to whisk that guy away or call up police.
You need to be aware of scams. Never show your documents or money to strangers that pose as police, yet they don't have official cloths or with the official police cars.
You don't need to be worry if you are traveling with your girl friend or boy friend , nobody would ask you of the proof of your relationship. Hotels are totally cool about it , so are visa offices.