that depends on whether they are air assist or not
and if air, then whether you have a compressor or not, however i am going to assume they are air you do not have a compressor.
If you look at the top of one of your fork tubes, you will see coming out of the side a schrader valve - just like is used on a tire. you can measure with a regular tire gauge, but be careful not to lose any air as there isn't much to lose. and then pump it to your desired pressure with a bicycle pump. (if you try to use compressed air be very very careful not to blow a seal! ) and that is all there is to it.
Your Interstate won't have the compressor so do like Barry says but be very carefull you don't put more than 5 - 10 lbs in. Check your capacity first so you don't blow the seals. I think the 1100 holds more than the 0 - 6 psi mine is rated for. I run 2 - 4 lbs.
1100 front fork spec is around 21psi. I regularly run mine around 40psi and have never blown a seal in over 15 years. Measure pressure with forks fully extended since it's such a small volume of air the pressure changes drastically when they're compressed.