How to quilt: choose your theme. Choose your design and technics. Choose your fabrics. Sketch and plan your quilt. Cut, sew back together, quilt.
Choosing your theme: usually your theme is what made you to consider quilting. Often people start quilting first time when they want to make a personal and comforting gift. If you are making a gift for a person you know, start with visualizing your idea about this person. Or, imagine a place your quilt will and up and make it to fit. I don't mean closet, because it's dark there and your design is irrelevant. Note that a quilt typically is a large thing. A practical bedspread will determine the color scheme of the whole room; a 30"x60" wall hanging is larger than your typical picture.
Choosing your design and technics: if you are new to quilting, consider simpler technics. Applique can be easier than piecing. If you go for piecing, you may want to start with strips and squares and avoid pieces cut on bias. Strip-piecing is an exciting method. Quilting by hand is slower than by machine, but you can do it anywhere, carrying small pieces in a zip-lock bag around. It is also easier to control. You can combine as many methods as your taste allows. I do 3-D applique on top of piecing and embroider on top of that and this way you can fake a very complex design.
Choose your fabric: that means choosing you color scheme and patterns. It is especially important in geometric designs. Generally speaking, dark pieces look smaller than light ones, and cool colors recede looking more like a background for warm ones. Lightness is sometimes confusing. To avoid the confusion, make a black and white photocopy of your pieces of fabric and compare lightness without color. Large patterns tend to distract from shape and break down geometric design, which is sometimes desirable. Contrasting strips have strong impact on geometric design -- use them consciously.
Planning your quilt to certain extent is necessary. Some people make colored sketches, detailed layouts, and plan exactly what fabric they use. This approach saves time, materials, and money. If you are going to make a traditional quilt with geometric piecing from new cloth, it makes great sense. If you are using leftover fabric, samples, or old clothes, colored sketch will help you to place different colors and shades to their advantage. Other people start with a vague idea and a primitive sketch, and make their decisions as they go. I make picture quilts with both piecing and applique. I usually start with a line drawing of a picture, measurements and templates for piecing, and a layout with crude coloring if there is more than one picture panel. I found that piecing takes more planning than applique, because sloppy piecing makes quilts that don't fit together or don't lay flat. On the other hand, there isn't much roon for detailed planning with complicated applique: fabric looks different than paper, patterns interact with shapes with unexpected results, and, unless you are making a life-size sketch, pictures don't scale very well.
Cutting, sewing back together, and quilting takes templates, scissors and rotary cutters, threads, needles, and a sewing machine, and lots of pins.
See also: quilting supplies, quilting fabric.