Typically, the following are allowed:

• 300 cookies in total
• 4096 bytes per cookie
• 20 cookies per domain
• 81920 bytes per domain

http://browsercookielimits.x64.me/

• http://www.jstorage.info/
• http://www.aboutcookies.org/
• http://cookiecontroller.com/

Flash Cookie management:

• http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager07.html
• http://en.wikipedia.org/wiki/Local_shared_object
• http://cookiecontroller.com/internet-cookies/flash-cookies/