Before starting a logo, think about the name.
Start with a list of words: list of feelings you want the logo to portray like: happy, warm, playful; then think about words that have to do with company of product your are designing for. For example a flower company, words would be floral, vase, green, stem, petals.
Then sketch out several designs in a sketch books. If you are using words, write the words 50+ ways in different styles, change the symbols with different shapes in sizes.
Review the sketches with client and allow them to choose the top 3 before using Illustrator.
Considering designing logos in Black & White first before adding color. Understand the logo will be used both in Black/White & Full Color. Switch Fonts, Symbols, and Color to present to the client.
Be flexible in designing. It is a good idea to view the logo at a business card size as well as a bilboard size. You want to eliminate all issues at the beginning so the client knows what they committing to. Logo is just the beginning in building a brand identity. Take great care in designing logos, you want your client to keep the logo for years to come.
Logo Design Resources: