I'm loving this inspiration today!  Keeping things mostly white with a few pops of color keeps the space from feeling overly-franchised, and I just can't resist that retro feeling rug!  These batman decals would also look really great on the wall, and if you need more concrete inspiration check out this room, this room, this room, and this room for some similar color palettes pulled of really well.  That vintage superman poster would look great scanned and re-printed at a much larger scale.

Sources:

(1) Cedar & Moss Pendant Light; (2) Brothers Pennant; (3) Bam! Poster; (4) SuperHero Nightlight; (5) Super Powers Poster; (6) Aqua Sconces; (7) Vintage Superman Poster; (8) Lighting Poster; (9) Metallic Pillows; (10) Maple Andersen Crib; (11) Flash Poster; (12) Vintage Dresser; (13) Aqua Shelf; (14) Silver Dot Bedding; (15) Super Hero Sign; (16) Everly Rocking Chair; (17) Stump Table; (18) Roller Rink Rug; (19) Black and White Bean Bag; (20) Metallic Storage Baskets