Q: One I cloud account multiple devices?

No, not with a single Apple ID for all devices. You are all then sharing the same iTunes Library and iCloud is syncing everyone to each other. If you want everyone to be separate, then they must all have their own Apple IDs and separate accounts on the computer.

Using More than One iDevice on the Same Computer

This applies mainly to couples who are adding another device and do not want their email, messages, etc. being duplicated on both devices. To begin read: How to use multiple iPhone, iPad, or iPod devices with one computer. You need to establish a separate Apple ID and password for whomever will use the new iDevice. See Apple - My Apple ID and Frequently asked questions about Apple ID. The easiest way is to do this on the computer using iTunes: iTunes- How to set up an Apple ID within iTunes.

On the computer create a new user account for the person with the new iDevice. This will be the user account that person will always use. He/She will no longer use the other user account. This way that person will have a separate iTunes Library

Start by transferring the new device(s) to a new account along with all your data.  Save any photo stream photos that you want to keep to your camera roll (unless they are already in the camera roll) by opening your Photos app, tap on Albums icon at the bottom. Now, tap on My Photo Stream album; tap Select; tap on the photos you want to select;, tap the share icon (box with upward facing arrow) in the lower left corner; then tap Save to Camera Roll.

If you are syncing notes with iCloud that you want to keep then you need to open each of your notes and email them to yourself. Later you can copy and paste the text into new notes created in your new account.

Tap on Settings > iCloud > Delete Account (only deletes it from this device, not from iCloud; the person keeping the current account will not be affected,) provide the password to turn off Find My Phone and choose Keep on My iDevice when prompted.  Sign in with a different Apple ID to create your new account. Choose Merge to upload your data.

Once you are on separate accounts, you can each go to icloud.com and delete the other person's data from your account.

Note: The essence of the above was created by user, randers4. I

have made substantial changes to improve readability and syntax.

What you are trying to do will create a mess.

Each of you should have its own Apple ID. The only place where the same Apple ID makes sense is in :

Settings > iTunes & App Store > Apple ID: > here to share purchases of Music, Books and Apps using the same purchasing Apple ID (ID with a valid credit card) so that you do not have to buy again for each individual devices.

All other Apple services like iCloud, iMessage, FaceTime, Game Center, etc. each should use thieir own Apple ID.

Read this tips for IOS 5 which is still valid till IOS 7.x:

iOS 5 & iCloud Tips: Sharing an Apple ID With Your Family ...