The first step is understanding the difference between copyright and trademarks.
Trademarks are a system for marking (distinguishing) one type of goods from another.
[quote]From Wikipedia: A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or services from those of other entities. [/quote]
Google is a trademark. The trademark ‘Google’ is not copyrighted. You cannot copyright words, nor can you generally copyright name. You can copyright characterizations. For instance, you cannot copyright ‘Harry Potter’, however, ‘Harry Potter, a wizard, etcetera’ can be protected. At what point is a bit murky. Example: it isn’t enough that ‘Harry Potter A’ and Harry Potter B’ both be boys. The movie Troll (1986) introduced the name Harry Potter, years before the book. Further, even though there are over 100 various Harry Potter trademarks now associated with the Rowling’s character, these trademarks cannot prevent anyone from having a character named Harry Potter. What they can prevent is the use of the phrase Harry Potter to mark any conflicting goods. Stay with me a bit here.
Troll is being remade. Even though the makers of Troll did not trademark Harry Potter, they can still use the name. What they cannot do it infringe on various ‘Harry Potter’ trademarks and call their movie Harry Potter Meets the Trolls, or Harry Potter VS Trolls, etc. This is not a matter of who used the name first. Trademarks protect how your goods (product) is represented in the marketplace.
An additional aspect of trademarks to remember is that trademarks are by area. So even if you find a trademark with the same name it may not prevent use if it only covers an unrelated area. For instance, registering a trademark for ‘Vehicles’ doesn’t mean someone cannot use that same word or phrase for clothing. This is why if one looks carefully at X-Men trademarks you’ll see various types of separate registration by Marvel/Fox/Etcetera to cover, not only comics, but entertainment, toys, games, and even cakes.
Copyright protects intellectual property. What some refer to as artistic or creative expression. Literally, it is the copyright owner’s right to control who can use the artist’s work. A list of the users of this site wouldn’t fall under copyright, but certain expressions of that list might. The standard example is that the information in a phonebook, the data, is not protected, but the form and layout may be.
The easiest way to avoid trademark issues is to make up something. That’s what Google did. You’ll still have to check to make sure someone else didn’t make it up first. Combining words can help, Balloony, Ballunacy, Ballunatic Attack, etc.
The easiest way to avoid copyright issues it to make your own art from scratch. Or Google copyright free, public domain, free art, royalty-free etcetera. Non-professional artists are often quite willing to allow you to use their artwork if you ask permission.