in your major scale you have 1(M) 2 (m) 3(m) 4(M) 5 (M/dominant) 6 (m) and 7 (diminished)
this means your first chord is major ,2 min, 3 min, 4 maj, 5 maj, 6 min, 7 dim.
in theory it is legal for the 1 chord to go anywhere
that is just the begining-im goin to try to chart this out-
--------------->(IV ) > (viio) > I>
iii> vi > ( ii )> ( V )>
<----------------------
in this chart, 1 goes anywhere, starting from the left, three can go to 6 and also to . six can go to (4 or 2 in parenthesis). 4 can go to 2 below it and also to (7 or 5 in next parenthesis) it can also go to 1. 2 cannot go to 4 but can go to 7 and 5. 7 can only go to 1. 5 can go to 1 or 6. chart this out for yourself with what i wrote below this chart and you will some the poicture. this one will help as a start though. keep in mind though that this is only the tip of the iceberg . you can do whatever you want musically as long as it sounds good but this diagram will show you some standard movements.
hope that helps-
zach 8O
