Someone has interested one of my domain and they wanted to buy it. However what are the best payment option for reselling the domain ?. What are the steps involve ? Such as do I lets the buyer to tranfer the domain to another registrar or i just give them my login information.

Thanks

Escrow is the safest way. www.Escrow.com they provide a service as do companies such as Sedo, Afternic, etc. I believe Escrow.com are cheapest and they are very reputable if that's any concern.

Someone has interested one of my domain and they wanted to buy it. However what are the best payment option for reselling the domain ?. What are the steps involve ? Such as do I lets the buyer to tranfer the domain to another registrar or i just give them my login information.

Thanks
The most optimum payment option can be decided by u and the buyer itself ..
And regarding the transfer of domain , once the payment is over u can hand over your domain control panel login information to buyer so that he can proceed further

open a sedo account,
add the domain
tell the buyer to buy through sedo

sedo will take a percentage, but it is safe and (suposed) to be a managed transfer (ie. sedo will email both partys)