I highly recommend that you use a password manager to manage and store all of the passwords that you use. Typically, most folks use the same password for many sites and accounts and are careless in maintaining their passwords; often storing them in and around the computer. KeePass will assist you in generating strong passwords and will assist you in securely storing your passwords. Also, check further on their website for ported versions of KeePass to other operating system platforms, such as Android. KeePass is available as a full install or portable app.
KeePass is an open source password manager. Passwords can be stored in highly-encrypted databases, which can be unlocked with one master password or key file.
Source: KeePass Password Safe