This has always been a problem for one of my groups-they view the rules as something that the GM tells them whenever things come up. Fortunately, they're usually pretty understanding when I say that I'm not going to run through every last possibility they could consider when giving them options, but I still wind up babysitting them a lot. (For instance, in my Savage Worlds campaign, one of them "didn't understand" the Test Drive rules, and he's an engineering student so I'm pretty sure that translates to "didn't read".)
Here's the things I wound up doing to get them to learn Shadowrun (and I'll probably wind up repeating with Savage Worlds to get them into it):
Can't explain it, can't have it.
Now, admittedly, this has led to some issues in my group, primarily with the invested players becoming infinitely more powerful than the non-invested ones, but I have a rule that if you can't explain how something works, you can't have it. There's a certain minimal floor for this; I don't require players to understand combat to have a gun, for instance, but if you want to hack/sling spells/take on advanced roles, you have to be able to explain the rules, sort of like how people have to take a test before getting a driver's license. This means that I don't have to explain stuff all the time, and it encourages players to read more.
Particularly in Shadowrun, which my players had the darnedest time with (well, most of them) because they didn't read anything, I'd place pop quizzes on them; this is essentially the "write-in-answer" equivalent of the "Can't explain it, can't have it." solution, where you ask people how many dice they use, the modifiers, the target, and why. I've pulled this on one of my players who was running a game once and he failed. At my table, if you fail a pop quiz, you get to go and read the appropriate section then and there, while receiving a helpful lecture on the rules. They never forget something after this, and it polishes up the rest of the group's knowledge. It does disrupt sessions a good deal, but it makes things easier moving on.
However, these are just really ways to deal with players that encourages them to work around the time investment. Here are some more practical ways to drive it home before you even begin.
- Explicitly state the investment required. I tell my players to read the books. They rarely do, except to try to break their characters (since most are pretty heavy powergamers), but even if one in four players actually reads the rules they can help explain them to the others.
- Be merciless. There was a sign in one of the Fallout games that read "Ignorance of the rules is no excuse for breaking the rules." or something long those lines (I think there was more swearing involved). If a player hasn't read the rules and creates a min-maxed character that doesn't work, I let them do this. For instance, my brother once built a d20 Star Wars character with exclusively odd-numbered stats to try to max out his modifiers. I forced him to play the character, and he went and actually read the rules to prevent it from happening again.
- Have a reading party. Have a session before the game starts where you go through the rules and discuss things. The success of this varies from group to group-I often justify it as being like practice before an athletic event, but if I don't make it mandatory, people won't read. The point of this isn't to read the whole book cover-to-cover, but rather to facilitate discussion of confusing rules. I often use a quickstart guide for these, since they're more concise (most of my players are college-educated or college-students and read pretty quickly when disciplined, though the more easily distracted ones don't always do well in this environment).
- Have an example run. Part of this comes from my limited experience as a game designer, but I find that providing examples is really handy, and I often show an incident between two NPC's with a complete justification for everything I'm doing-this also confirms my own knowledge of the rules, which is helpful for staying consistent in a long campaign with a complex game.
- Confirm your book "kills". This is perhaps something that works better for veteran roleplayers, (or reviewers like myself), since they've had access to more games, but I like to have the sort of "notch on your gun" discussions with prospective players. Basically, I recount stories of how much I've read, toss around some page counts, and things get serious. "I've read over a thousand pages of Eclipse Phase. Twice." Players listen after that, and at the very least you can usually get them to read the basic rules. In short, it's okay to brag to put the paltry reading you're having a player do in perspective.