There is no other better services provider in India than Airtel and to get better services they suggest you to go for their official site for Airtel Mobile Online recharge to avoid any sorts of troubles.
There is one slighter advantage if you recharge your mobile through Airtel Site, you will not be charged any additional charges like taxes, miscellaneous fees, transaction charges etc.,.
This how to get started for recharge of your Airtel Mobile.
1. Open Airtel India Official Prepaid Mobile Recharge Page. This what the interface looks like.
2. If you are registered user at mcheck then you can directly proceed to directly recharge option but if you are registering for the first time then you need to register your mobile for mcheck.
3. Once done you can recharge your Airtel mobile through your Credit Card or Debit card or Internet banking facilities with the major banks in India.
That complete your Airtel Online recharge procedure, as easy as it is. You know you can also recharge your DO CO MO Mobile through Online also at Official Do Co Mo site.
So which one would you prefer
Online Recharge or Offline Recharge

Not just Airtel but the other networks help with recharging the phone online, but it would have been great if there was any one stable website or client which allows the recharge of mobiles by paying through online processors like Paypal etc.