1. Open form in design view
2. Right-click on its title bar
3. Select Properties to open the form's property sheet

If you only want to use the form for data entry and not for editing, then
click the "All" tab and then find the line for Data Entry. Change this from
No to Yes.

If you always want to begin at a new record but also allow existing records
to be view and edited in the same form instance, then you have two options.
******************************************
Option 1 (not always the best approach): follow steps 4 thru 10.

4. Click on the "Events" tab
5. Click on the words "On Load"
6. Directly to the right, click the down arrow and select [Event Procedure]
7. Directly to the right of that, there will be a button which looks like
[...]
8. Click it to open the vba editor
9. You'll now see some text which looks like the following:
Private Sub Form_Load()
End Sub

On a blank line between those two, you'd type:
DoCmd.GoToRecord ,, acNewRec

10. Click the "Save" button and then on the application's menu bar, go to
Debug | Compile. If you get no errors, close the editor, and then the form.
Then re-open the form normally to see if it works like you want.
****************************************

Option 2 uses a command button on another form:

Follow steps 1 - 3, but obviously opening a different form
Add a command button by clicking on the toolbox
Follow the Wizard dialogue
When finished, right click the new command button and click "Build" to open
the vba editor. On a blank line directly following "DoCmd.OpenForm .....

type: DoCmd.GoToRecord ,, acNewRec

See #10 above
*******************************************

HTH,
Brian