The appropriate attire for job interviews is business attire or business casual, depending on the type of job. You want to dress to impress, but not by making a fashion statement. Heels are appropriate for a job interview, as long as they're conservative and don't take attention away from your face. Appropriate heels look neat and polished. They're subtle in color, match your outfit and aren't too high.
When it comes to style, you don't want to go overboard; avoid extremes and go for a more conservative, timeless look. Leather, suede and fabric are good choices for the texture of your heels. Closed-toe pumps are generally the most classic for business attire, but open-toe pumps are appropriate too. Don't wear wedges, platform heels or 4- or 5-inch stilettos. Only wear a heel you can walk in with comfort and ease; if you're wobbling you won't look as professional. According to ExecStyle, 2 1/2 inches should be the maximum heel height worn for a job interview.
Your heels don't have to be new, but you want them to look well taken care of and not worn out. Don't wear heels that are scuffed and scratched, and be sure that your heel tips aren't worn down. It never hurts to wipe your shoes with a gentle cloth to remove dust and add polish.
For a job interview, you want your portfolio, the way you carry yourself and your attitude to stand out -- not your clothing or shoes. Boring shoes would never constitute a reason to not hire you, but over-the-top heels could cause a conservative employer to pass you by. Avoid bright-colored shoes, heels with spikes, fishnets and other unconventional styles. Stick with dark or neutral solid colors, and avoid intricate designs that draw attention to your shoes. If your heels are open-toe, make sure your toe nails are clean and presentable.
Alternative to Heels
If you don't have heels that are appropriate for an interview, there are perfectly appropriate alternatives you probably have in your closet already. Higher heels are very appropriate for many professional jobs; but other jobs are more casual in nature, and nice leather, suede or fabric flats may be more appropriate. However, they should also be conservative in style and texture, dark or neutral in color and complement your outfit.