How many pieces of art do you need? And their sizes? Images that hang in halls and up staircases should be smaller and more intimate because you cannot stand back from them. Pieces of art that need to be read from distance have to be larger and stronger.

Where do you need artwork? Here are few suggestions...

Foyer - over hall table

Living Room- over sofa, over fireplace
Dining Room - over buffet
Master Bedroom - opposite bed
Kitchen - over kitchen table

Den
Hall - down hall
Master Bath
Child's Room 1
Child's Room 2
Other

What kind of Subject matter do you like? Remember, there are no right answers. There is wonderful art to be found in all categories:
Abstraction - Geometric
Abstraction - Lyrical (soft , Frankenthaleresque)
Abstraction - organic
Water
Landscape
Figurative
Still Life
Urban
Floral
Portraits

What kind of Colors do you like? Again, no wrong answers. You don't want to match everything. Remember the art you like will reflect the palettes that appeal to you.

Bright, highly colored
Soft, pastelly
Black and White
Neutral, minimal

What kind of mood do you like?

Surreal - realism with oddness
Realistic - photographic
Realistic - romantic landscape
Expressionistic - wild painterliness
Quiet, zen-like minimalism
Mechanical - scientific
Impressionistic
Humorous
Elegant
Traditional

How much do you want to spend? You can always find something you love in any price range.

Investment quality- have tons of museum retrospectives, catalogs. Can get original prints at reasonable prices.
Solid well-established - typically in small museums. Artists who have good bios.
Young, cheap and speculative.