Colleges and SAT, help please!

<p>I read in some threads a while back that US colleges take the best scores from each section, is this true?
Also, the unwritten rule of writing it three times - what if I take it a fourth?
(I wrote it in Jan to see how I'd do, going to write it in two days but spent majority of time last and this month studying for AP's, so hopefully I get one more chance or two)
Last thing - If there is steady improvement from one SAT to the next, is that a positive thing? And do colleges even see my previous SAT scores?</p>

<p>Thanks in advance!</p>