Cisco offers different "tracks" when it comes to certification:

• Routing & Switching
• Design
• Network Security
• Service Provider
• Service Provider Operations
• Storage Networking
• Voice
• Wireless

Most of the tracks have 3 "levels" of certification:

• CCNA (Cisco Certified Network Associate)
• CCNP (Cisco Certified Network Professional)
• CCIE (Cisco Certified Internetwork Expert)

The most popular track is routing & switching, most people first start with routing & switching and take on another track later on. If you are interested in configuring networks for VoIP you will need to know some routing & switching protocols, especially quality of service. Implementing security is also kind of hard if you have no idea what to secure...

On the Cisco website you will always see this pyramid when they are talking about certifications:



At the bottom you see the "entry" level, I'm skipping that one and jumping right to the "Associate" level (CCNA) because that's where most people are starting. As you can see the bottom is very width, and if you go to the professional (CCNP) and expert (CCIE) level it's narrow.This image is chosen for a reason.

CCNA

If you start with studying Cisco, you'll start with the Associate level (CCNA). There are a lot of topics and technologies that you might have never heard about, so there's a lot of studying for you to do...I believe this makes it a hard exam for newcomers. If you want to self-study for CCNA I recommend you to get this book:
 CCNA: Cisco Certified Network Associate Study Guide: Exam 640-802



It covers all the topics for the exam, if you read this book a couple of times and do all the exercises...you'll have a very good basic understanding of networking. It shows you the basics of networking, switching, routing, ip, etc.

You can get the CCNA certification by doing 2 separate or a combined exam. If you do the combined exam you need to get a higher score and I only suggest doing this when you feel really confident about your networking knowledge or already have experience.

To beat Cisco exams you need to get hands-on experience. You can achieve this by buying old equipment (from eBay) and practice. This is what you will need at least:

2x Cisco 2950 Catalyst Switch. (any version will do)
2x Cisco 2610 Router with at least 1x Fast Ethernet and 1x Serial Connection.
1x Serial Console Cable (those are the famous blue Cisco cables for console connections)
1x Serial Cable
1x Serial 2 USB (in case you don't have a serial port on your PC or laptop).

If you are planning to continue studying Cisco I would suggest to buy Cisco 2550 Catalyst Switches instead of the 2950's, they are more useful for your CCNP.

It's possible to skip the routers because you can run Cisco IOS (Cisco's Operating System) on your PC or laptop by using GNS3. You can find a brief tutorial on GNS3 here.

Cisco 2610 Router

Cisco Catalyst 2950 Switch

Cisco Serial Console Cable:

Cisco Serial Cable:

CCNP

This equipment and the study guide should help you to pass your CCNA, Now if you want to continue studying your CCNP you will find that this is much easier (that's my opinion) then when you studied for your CCNA. When you started with the CCNA you had to study complete new material that you perhaps never heard or read about before, now you have a basic level of networking knowledge that you will further develop.

To achieve your CCNP certification you need to pass 3 exams:

• Route (Routing)
• Switch (Switching)
• Tshoot (Troubleshooting)

For passing your CCNP I'd suggest to read the following books:
Routing TCP/IP Volume 1:
This book isn't special for the CCNP but covers all the interior routing protocols and is written very well, a must read for every networking professional.



Routing TCP/IP Volume 2:
Sometimes more is better and that is definitely true for Routing TCP/IP. This book is more about BGP (Border Gateway Protocol), NAT and some IPv6.



The other books you should read are the Cisco Press books that cover the exam goals:
CCNP Route:
This is the official Cisco Press book, covers everything you need to know for the "Route" exam.



CCNP Switch:
Also the official Cisco Press book about the Switch exam. Teaches you everything about switching you need to know to pass the exam.



CCNP Tshoot:
Troubleshooting networks is fun, this book will show you everything you need to know.



Besides reading books you need to increase your hands-on experience...do more labs, build networks and so on. You can do a lot of labs with routers by using the dynamips/gns3 software. Checkout my tutorials on GNS3 here.

The new Cisco exams are very "practical". This means you will get a lot of questions you cannot answer if you don't have the hands-on experience. You need to build networks...do labs, try stuff out. Just reading the books is not going to be enough!

CCIE

Now the CCIE is a completely different beast. Honestly you can't compare this to CCNA or CCNP level. To pass the CCIE you need to do a written exam and pass the lab.