Creating documents isn't only about adding information; you also need to be able to quickly delete what you don't want. Annoyingly, Excel makes this more difficult than it needs to be.
When you select several cells at once, use the <Delete> key to remove the contents; if you hit <Backspace> it will delete only the contents of the first cell and leave the others.
If you want to remove the cells rather than just the contents, right-click and choose "Delete..." - you get the option of moving the other cells up or left to fill in the space.
If you've already removed cells from a worksheet, cleaning up the spaces that are left is very simple - assuming you've removed whole rows. Select your data (click the top-left corner of your worksheet to highlight the whole sheet) and choose Data-Sort. Pick a column to sort by, set it to Ascending and you'll get information at the top and blank rows banished to the empty section at the bottom.
You can achieve the same effect if you have headings for your columns by selecting them and choosing Data-Filter-Autofilter. This will provide you with a drop-down menu on each column in which you can select Ascending to sort straight away (see Figure 1).
You can also use the Autofilter menu to choose Blanks. That will show only the rows where the cell in that column is blank, even if there's data in the other columns.
Edit-Go To-Special-Blanks will select all the blank rows and blank cells in columns that have information in other rows. It's usually best to get rid of blank rows first because trying to delete blank rows and cells at the same time can give confusing results.
To delete quickly in Word, the trick is getting the selection you want. Double-click to select the current word; click three times to get the paragraph. Clicking at the side of the document selects a line; click twice for the paragraph and three times for the whole document (or the section if you've divided the document). <Ctrl>-<Delete> removes the whole word in front of the cursor (or the rest of the word if you're in the middle of it); <Ctrl>-<Backspace> takes the whole word before the cursor.
Deleting rows and cells from tables in Word is easy but slow if you use the Table-Delete menu. The <Delete> key clears the cells but leaves the table. The <Backspace> key deletes the contents and the selected cells; if you have a row or column selected it vanishes, while if you use <Backspace> with a cell selected you get the "Delete Cells" dialogue (see Figure 2). You can do it faster by selecting what you don't want and using <Ctrl>-X to cut it out.