Green Card for Oerseas Husband

[immihelp]

Would you please direct me to the place where I can find this information:
My husband and I were married while he was here on a visa waiver, and he left prior to the expiration date.

Now that he's out of the country, I am applying for his green card (since they don't let you apply for a change in status when here on the VWP).
My question is this: if there is a green card application pending, can he return to this country again with a visa waiver? He is in the U.K.

Please refer me to where I can find this information.

Also, if I should go to an immigration lawyer to complete the forms, please refer me to whom I should go.

I live in the Washington DC area.

Thanks so much!

[immihelp]

Yes, he can.