All heads come with a fully line Neoprene inside. Though I would advise to get a Balaclava to help keep the head cleaner.

If you have a full suit invest in under armor as it will keep you feeling cool and the suit much cleaner. If you can afford it an Ez cool vest can be a real lifesaver as it keeps your chest nice and cool in suit.

Please brush your suit. And yes fleece can be brushed! Use a small bristled brush similar to a horse brush and gently brush the fleece. For a normal Fursuit use a dog brush. Be careful over small sewed markings and paint.

Combine isopropyl rubbing alcohol and water at a 50/50 ratio to make a disinfectant spray. Gently spray once or twice in head or parts to disinfectant. Gently take a towel and rub in the alcohol.
Do not spray the eyes as they can warp or run the paint.
Flip the suit and parts inside out if you can and spray a few times over them. Gently rub in the alcohol.
Leave parts and head to hang and dry on a fan. This will also air out the suit. 
I recommend brushing each time after suiting as it will make it nicer and last longer.

Ask maker before washing suit!
To wash a suit or body parts fill a tub with warm or cool water. Not too hot! If any parts are heavily airbrushed flip inside out and use only cold water. You may wash all parts save for the head so long as they have no colorful dyes and were approved by your maker.
When soaked add a gentle detergent such as woolite. Only enough to make some suds.
If you have a problem stain use baking soda. Oxiclean or Folex is also good for white fabric to get tough stains out.
Scrub every area of the suit especially areas prone to matting
To get matted fur out scrub and brush under hot water. Use with caution as this can damage the suit!
When draining squeeze as much water out as  you can and gently rinse the soap out.
Use a towel and laundry basket to transport your wet suit.
You could also wash your suit in a washing machine. Be sure to ask the maker if this will work!
Place the settings on cold and gentle! And use a gentle detergent. Make sure their is not steam cycle or heat whatsoever!
A suit can also be put in a dryer if no heat is applied whatsoever.
To dry your suit lay it down on a towel and flip it so the fur is outside again. Gently brush the suit every few hours and after awhile you can hang to dry. Don't store until 100% dry. Feet and parts with foam will take much longer to dry.

The best way to store your suit is in a closet with room temperature and little light. Storing in a tub over time can lead to creases.
Place a dryer sheet in head, hands, feet, and suit to absorb moisture and leave your suit fresh!

The Major Do Nots!

Do not ever use heat on a fursuit!

Do not ever take it to the dry cleaners!

Do not store your suit after suiting or washing! The moisture will cause mold!

Do not hang a suit to dry! This will stretch the fleece or fabric due to the weight!

Do not ever submerge your head in water without consulting the maker!

Do not use Febreze, Lysol, or other harsh cleaning chemicals!

Do not cram the head or parts in a container! This can leave a permanent bend in the head!

Do not leave suit in a hot car for too long or in direct light! The glue will melt and the color will fade!

Stay away from foods and drinks that stain!