Help With Joins

I'm quite new to Microsoft sql and so please forgive me if I appear a novice. However, could someone please give me help with the following 2 queries:

1. I need to retrieve the names of each ward that currently has at least 5 resident patients.

2. I need to retrieve the names and ward numbers of all patients that have been referred to the Dermatology department (this data is in the doctor specialism column).

The db has the following 4 tables:

doctor
(
staff_no CHAR(3),
doctor_name CHAR(12),
position CHAR(15),
specialism CHAR(15),
PRIMARY KEY(staff_no)
)

nurse
(
staff_no CHAR(3),
nurse_name CHAR(12),
ward_no CHAR(2),
supervisor_no CHAR(3),
PRIMARY KEY (staff_no),
FOREIGN KEY (ward_no) REFERENCES ward,
FOREIGN KEY (supervisor_no) REFERENCES nurse
)

patient
(
patient_id CHAR(3),
patient_name CHAR(12),
consultant_no CHAR(3) NOT NULL,
ward_no CHAR(2) NOT NULL,
PRIMARY KEY (patient_id),
FOREIGN KEY (consultant_no) REFERENCES doctor,
FOREIGN KEY (ward_no) REFERENCES ward
)

ward
(
ward_no CHAR(2),
ward_name CHAR(10),
number_of_beds SMALLINT,
PRIMARY KEY (ward_no)
)

Any help would be appreciated