Grade 4

The following is a comprehensive list of all the 4th grade daily exercises from Evan-Moor Educational series.  I don't believe in doing too many drills but once you get the concept, it doesn't hurt to pick and choose some exercises reinforce the skills.  These books are used widely by elementary schools.
 
Grade 4 Workbooks
Book Cover Link to Site Description
Daily Academic Vocabulary Daily Vocabulary
Daily Paragraph EditingEnjoyable reading while proofreading.
Daily Math PracticeDaily Math exercises similar to state standard tests
Skill Sharpener MathDaily Math exercises similar to state standard tests
Weekly Spelling, Math, Cursivechange the file name to get access to all the worksheets (hw2001-hw6001; hw8001-15001; hw17001-etc ...)
Daily GeographyClick on the links of each week lesson to get the weekly exercises.

Below is a list of websites by dedicated teachers:
What is missing in this list:  analogies and logic/puzzle problems.