Two key points - don't shrink after load, it will only cost you next time around; and checkpoint after each COMMIT to clear completed transactions from the log.
Grant Fritchey has an excellent blog entry [/url]which may help.
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden