Yes, White Star is awesome and it just came it out. But there’s already some pretty hand stuff that came out before White Star that you can use with it. Now this is based on my own tastes and I may not mention something. Also, this is stuff I already have so your mileage may vary.
For adventures there’s Dungeon from a Distant Star, and for X-Plorers Cleopatra Station. Speaking of X-Plorers grab it up and you could easily get some mileage out of the Alien and Robot Design.
There’s some handy class stuff in Strange Magic. Most are for fantasy campaigns but the Reverend Sisterhood is take on the Bene Gesserit from Dune.
For just charts, miscellaneous inspiration, and what not:
Bandits & Battle Cruisers has a ton of charts and monsters that’d be easy to convert/tweak.
Starship from Hell: A system agnostic book for generating ships, their crews, and plot hooks.
Frontier Explorer and Star Fronitersman while these are both for Star Frontiers there’s plenty of adventure seeds you can grab to get you going.
Galileo Games has some freebie adventures for Bulldogs! (FATE). An easy bit to convert and more adventure ideas.
Machinations of the Space Princess has some more handy charts and some inspiration. There’s a starship critical hit chart that would work well with White Star and some easy planet charts. There’s a few of bits you can mine for inspiration or house rules.
Vornheim Yes, I know it’s designed for fantasy games but there’s just so much inspiration and useful tools in this little book it’s not even funny. Just a adjustment on tone and there you go. Or you can just over to Mike Evan’s blog and grab up his Firefly/Vornheim hack.
And finally and by no means the least. For inspiration for a setting or more alien races. Get Strange Stars. I mean grab it now right now. Chances are you’ve heard good things about this. Well, they’re true. So if you haven’t gotten it already then grab it up.