Within a CRM form there are many hotkeys that will help you enter data.

You can use these key combinations to save, save and create, or delete the record.
Save = CTRL-S
Save and Close = ALT-S
Save and New = CTRL-SHIFT-S
Delete = CTRL-D

When a drop down list is selected, UP and DOWN can be used to select the different options. Pressing a letter key while in the list will retrieve the next value with text starting with the letter.

Multiple records can be selected by using SHIFT and UP or DOWN, SHIFT clicking, or CTRL clicking items just as you would in Windows.

To edit multiple records, first select the records you wish to edit, then click the 'More Actions' button and click 'Edit'. This will load a new form where any changes made, will be made to all selected records. All unmodified (blank) fields will not affect the selected records. This feature is not available for all records and does not allow you to update all fields, but is excellent for bulk updates.

Keep in mind that Microsoft made this program very intuitive in its functionality, so play around with it or look online to see what other features are available.