Hi,
Im being trained in to Asterisk and VoIP. Due to this im also aiming to get my dCAP by Summer.
Ive read through Asterisk: Future of Telephony and am currently building test servers and trying new things. Problem is ive no idea what i should do to prepare for the dCAP, im used to college where I can use past exam papers to study with lol! 
I was thinking of getting the Asterisk Essentials pack off digium as a way to help me learn and was wondering if anyone has used it to learn asterisk before and if it helps more than browsing random youtube videos?
Asterisk Essential videos will be very useful for you . they are high quality videos that teaches asterisk very well . but if you have read the Asterisk the future of telephony book and you have the required experience on the subjects you read you will be pass the exam .
You can apply the DCAA test and see where are your weakness before going for the DCAP.
Great to hear you are enjoying Asterisk Essentials!
The dCAA Exam is available to take free online:
digium.com/en/training/certifications/#dcaa
The best preparation to pass the dCAA is to take one of:
Asterisk Essentials (online) or Asterisk Fast Start (Instructor Led)
digium.com/en/training/courses/#essentials
digium.com/en/training/courses/#faststart
The dCAP Exam is significantly more challenging and involves both a written and a practical (configure a server) exam:
digium.com/en/training/certifications/#dcap
The best preparation to pass the dCAP is to take:
Asterisk Advanced (Instructor Led)
digium.com/en/training/courses/#advanced
dCAP is designed to test not only knowledge, but ability. So practical experience configuring Asterisk servers is the way to prepare. Good luck!