the cheapest will be (around 1.50 a peace for the 1" ) at OFFICESUPPLY or COSTCO or TARGET
If you want the convenience of AMAZON shopping the cheapest would be here (for around 2.50 the 1").
For a great selection of binders for all sizes, tastes, and budgets go here.
the regular size would be 8 1/2 by 11 inch and there are two kinds the one with wide lines (wide ruled) this will give you a nicer space for writing but it will fit less on the page or you can go with college ruled what gives you more on a page.
For the wide ruled you got a pretty good price for good quality paper with nice lines on Amazon
and you can find a bargain but not the same good quality at target .
For the college ruled you can get nicely packed at 100 per pack here
or by 500 paper pack for a little cheaper here
then there is the more expensive stronger and nicer version with More durable, patent-pending triangular holes and stronger reinforcement tape resist tearing from rings. here