For obvious questions, one of the most often asked questions on this board is for recommendations for new readers.
And there are plenty of choices available.
There's some excellent material available in various reprint collections. You could find most of these stories in well-stocked bookstores or internet retailers.
There are also fantastic stories that have never been reprinted, or that were collected in volumes that have since gone out of print. These stories may require a bit more searching, but it should be well worth it.
And Marvel's making an effort to have digital comics available, either on their website or on the Ipad.
You could just start picking up the title during its next jump-on point.
* Edit- Or the most recent jump-on point (Amazing Spider-Man #648) collected as part of a hardcover.
And there's a new thread about mini-series and one-shots.