Validate a model and select the best model fitted

Hi, I have a doubt.
I have fitted some data to different non linear models minimizing the sum of squares.
Then I have calculated the AIC and BIC for every model and I have chosen the model with lower values of AIC and BIC.

Do you believe that it is sufficient to choose the best model?
then of minimizing the sum of squares I need to do something more??

thanks in advance for your help.