I just finished SOCS 350 (Cultural Diversity) and NR 351 (Transitions), and they worked beautifully together. I thought the Transitions class was super easy.You'll have to make 4 posts per week in the Transitions class and 6 a week with Cultural Diversity, so keep up with those and try to get them all out the way early. You have to contribute to each discussion in either class no later than Wednesday, but again, you don't want to wait until Wed. to get started, do it early. You'll have about 3 mini papers (don't remember exactly) for Socs 350 and then a large project (6-8 pages) due at week 7. Don't wait until the last minute to get started on this one. I was done with mine at week 3 (because I preferred to do my outline based off my already written paper), so all I had to do was some tweeking around submission time.
Also, for the Transitions class, you WILL NEED to buy the APA manual. I didn't at first, until we got to an assignment that required it, and then I just went to my local bookstore (Books-A-Million) and bought it. However, I did purchase another APA guide from Amazon called "APA: The Easy Way" 2nd edition. (Houghton, ISBN# 0-923568-96-2) and I found myself using it more than the required manual, especially when I needed to set a page header (p.5-6).
If you read your syllabuses and follow them exactly, along with your grading rubics, keep up with discussion postings, assignments and lectures, you'll do just fine.
Best wishes with your studies! You can do it!