In the Settings you just enable the Personal Hotspot (iOS 5). Then you connect your iPad with your iPhone (if you already paird it) and it is connected - Voila.
Your iPhone also needs to be 3GS or later model to have this feature. Some telcos also charge for this service so it might be an idea to check this out.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.