You might start by checking out the "Nordic Countries" forum on this site (in the Destinations area).

Sweden and budget aren't really words that go together, but still lots of ways to keep costs down.

I like the Lonely Planet series of guide books. They seem more budget oriented than many others. They have books specifically on Sweden. You might find them in a library. Sometimes prior year's editions are available for less money on Amazon.com.

Youth hostels can be great places to save money and also meet up with traveling locals. Click here for one I've always wanted to try.

Backpacking, grocery stores, picnic lunches.

I like the way you've started thinking of your trip. My first trip to England, my goal was simply to drink a pint of bitters in a pub.

Romelle