How much can a debt collector take from my check on a weekly basis. They have garnished my wages. Also can they garnish my bank account??

Most state have a limit on wage garnishments, and yes they can attach your bank or any accounts they find.

How much can a debt collector take from my check on a weekly basis. They have garnished my wages. Also can they garnish my bank account???
What if the bank account is in my husbands name and I am just a signer?

They will attach it, but the other party o the account can file a third party claim against the garnishment.