Wizards of the Coast releases new Magic expansions every three months. On their site (the mothership) at http://magic.wizards.com the articles section has a gallery with images of each card.
A few weeks before each set is released, preview cards are distributed to writers, podcasters, vloggers, and other content creators, to help them promote their feeds and their content. Each evening, all previewed cards are added to the mothership. By revealing a few cards at a time, Wizards foments a discussion about themes in the set.
When you see these first cards, you’ll know they are emblematic of what the set is trying to accomplish and what it represents. Still, the power of a card is so dependent on which other cards it’s balanced against, that you can’t really know how good it is without seeing the whole set. So, by revealing cards gradually, Wizards adds clues to an incomplete picture.
Once the full set is spoiled, the Card Image Galleries are a super source for card details. There are also databases with advanced search (such as http://gatherer.wizards.com), but I like the gallery for the fastest reading experience.
As you understand how the new cards work together, you will notice some that seem really good, and others that could work excellently together. Magic is complex enough that no one can “solve” the format before the cards are released and the Pro Tour commences. So, at least for a few weeks every season, your deck ideas are as valid as anyone’s.