The old souk buzzes just like you'd expect an old arab souk to. Go after dark when its a bit cooler. Lots of open fronted market stalls and gold shops. And haggling. There are probably bargains to be had if you know what to do.
Provided you know where you're going and you're not a woman on your own, much of Jeddah is quite safe to explore, but because it's a strict Muslim state, there are things you need to respect. Everything stops and shuts up for prayer for an hour when the sun sets. Strangely, this happens to be the busiest time on the roads. I'm told that you're excused from prayers if you're travelling. On the subject of the roads . . . be afraid . . . be very afraid.
Quick Tips:
Tip one: There are a few restrictions on what you can and can't do, especially if you're a woman. And it's quite difficult to get into Saudi. You normally have to be invited in by someone.
Tip two: If you're driving, find a way of looking in all directions. It's every man for himself.
Tip three: Traffic lights are there for GUIDANCE only. If you're waiting at a red light facing two busy lanes going across, don't be surprised if the guy next to you fancies his chances and makes a break for it.
Tip four: You don't get windscreen washers in Jeddah. Instead you get people trying to sell you things when you're stuck in traffic. Usually it's chewing gum, but sometimes it will be a parrot in a cage or something like that.
tip five: You're not supposed to take photos of anything (nobody really knows why), so you may get your film confiscated at the airport.
Tip six: The Saudis have a very strict interpretation of what pornography is. Be prepared to have brazen hussies like Britney Spears obliterated with magic marker from any magazines you might be carrying on arrival.
Tip seven: No drinking.
Best Way To Get Around:
Jeddah is vast and sprawls for about 25-30 miles along the red sea coast. You also need to know where you're going. So if you don't have a guide, get your hotel to sort you out with a taxi. He'll also know where it's wise to go and where it's not.