Select the view as per your need, may be Day view, Week View or Month View. But i wil suggest days View. You can select any number of days. so it will displayed with timeline as below :
Just click on the timeline and add the event. That will be a simple task i need not say how to do it.
Click on the settings button to view a page like this :
This page will show the calendars you have. Since i have only one calendar, its shows one. You must click on Notifications to set the notifications to mobile.
You can click Mobile Setup to add your mobile to Google Calendar.
Type your mobile number to which you need the notifications to be sent in. You will get a verification code to the number. Type it in the text box provided for verifying.
To set notifications, click the notifications,to see the below page:
In Event reminders sections, select Add Reminder. Choose SMS and specify Time and save the settings. Now you can receive your todo to ur mobile time which u specify :) :)