If, nested if, hlookup, vlookup

Having some issues with a large amount of data on my spreadsheet.

1. I need to use an "IF" statement to determine current Deans List students. Students with a GPA of 3.75 or better. I need to insert "Dean's List in column J for those who qualify. Students who do not qualify should have a blank in column J

2. I need to use a "Nested IF" to determine the class ranking for each student: a. Senior=>90 Earned Hours, b. Junior =>60 Earned Hours c. Sophomore => 30 Earned Hours d. Freshman <30 Earned Hours and e. Graduate

3. I need to use hookup with a match to determine each students advisor. The advisors are listed in my Advisors Table (V7:Z10). Additionally I need to use hookup to find the Major and use a match function in the row_index_number

4. I need to use lookup to assign a letter grade to the students GPA. The GPA's are in my grade table (Q6:R11)

5. In range S6:S10, I need to count the letter grades - how many A's, B's, etc....

I have been working on this for hours and right now feeling really frustrated. Any guidance is greatly appreciated......