07-31-2012 10:38 PM
You can start by downloading the latest BB10 simulator from here: https://developer.blackberry.com/native/beta/downl
Also, keep your eyes open for news of upcoming "BB10 Jams" and/or other opportunities for getting the Dev Alpha, which is the only BB10 device which developers can actually get, aside from the simulator. There are still three more scheduled Jams coming up, and you could register if one is accessible to you: http://www.blackberryjamworldtour.com/register
If none of those are suitable, you have little choice but to wait for more news. RIM has said they will make more Dev Alphas available, but they have not yet described their plans for how that will happen. If you actually pay any attention to the matter, you'll hear about it. Best is probably to follow @BlackBerryDev on Twitter since anything important will be mentioned there.