The only online lab I'm currently aware of is VMware's HOL which currently is a public beta
Anyway, take a look at http://paulgrevink.wordpress.com/2012/12/31/vcap5-dca-study-guide-is-now-available/ for a excellent Study-Guide.
André
Hi Andre,
Without Lab it is ver difficult to prepare for VCAP.. Just Up grade your present Home PC with some Higher config and Install ESX on Vmware Workstation. This can help you ....
IMHO, consider also a self virtual enviroment, for example with Autolab.
http://vinfrastructure.it/en/2012/05/building-a-vsphere-5-lab/
Also do not forget the #vbrownbags series which provides full video coverage of all of the areas of the blueprint that need to be covered. This is an excellent resource and you can subscribe to podcasts and download to your ipad/iphone or laptop - very handy while commuting . And on Pluralsight.com (previously called trainsignal.com) you can also find the troubleshooting videos which are quite useful.
As well as Paul Grevinks great links I also found valcolabs.com and thefoglite.com very useful in helping me pass.
But as Andrew pointed out you do need a lab. Probably you will "get away" with a PC with 8-12GB of RAM and I would highly recommend SSD drives otherwise it will be very slow.
Hope that helps...