Should I get a full suspension bike, a fork suspension one or a single pivot suspension?

Im looking for a cross country-city bike to commute to college and work and to do long tours on weekends, mostly off road. I have read the wikipedia article about suspension and im still confused. THe city where I live has not the best of roads and a lot of high sidewalks, not all asphalted surfaces are smooth. Thats why I want a decent suspension to:

1. Not harm the bike every time I hit one of those
2. Not harm myself
3. Be able to increase the distance I am able to ride on a single day.

On weekdays I'll bike with books on the carrier and groceries: say 12 kilos

Which suspension would you get and why?

Article under https://en.wikipedia.org/wiki/Bicycle_suspension

 

Full suspension is for single-track trail riding. Is this what you mean by off-road touring?

 

with offroad I mean simply on earth tracks, can but must not be trail riding

 

I would not get a suspension fork. It's extra weight and complexity you don't need. I ride trails and paths and see no need for it.

 

Do tell how much you're willing to spend. That is one thing you need to bear in mind when getting a bike. less than $1000 and you better stick with a quality hardtail. if you can spend more, then a full suspension bike will make sense.

Why price? Well good suspension costs money. High end bikes and even entry level suspension forks and shock would cost upwards of $400 and up to $1000 (just the fork).