There's a report on open.silverstripe.com listing all tickets which have the keyword "easy" added to them. This means that we assume they're not too much of a hassle to fix if you've got a good understanding of CSS, JS or a moderate understanding of SilverStripe core features.
We'd appreciate if you can help out with any of these tickets - if you're working on something, please add a comment on the ticket. If you're fairly sure you can solve the ticket within a reasonable timeframe, reassign to you.
The full list of core defects can be found here (for the more ambituous contributors):
Thanks for your help!