I've shaved my head for 23 years. Always just use soap while showering. Started out using single blade Bic's but for the past several years have used 3 to 5 bladed Gillett's. Excellent razors and results are silky smooth.
Wish I could shave everyday but due to razor burn I needs at least a days stubble betweens shavings.
Once I get that initial post winter burn on the dome I can generally go all summer without a hat and I never use sun screen. I do caution you though should you choose to go that route you may want to wait until the peeling is done before shaving cause the blades tend to snag on dead skin.