You will need the following items in addition to a catalog and album system when beginning your stamp collecting hobby.

Stamp tongs - these are basically a tweezers designed for handling the thin pieces of paper you are going to collect. Buy a good pair, with thin edges at the tip. Cheap stamp tongs are thicker metal, and it makes picking up stamps difficult/

Perforation gauge - these inexpensive, usually paper, gauges help you determine how many perforations per inch a stamp uses. Stamps used to come with different perforation patterns, or perf's, and there are some where the perforation is the only difference between one stamp number and another.

Watermark detectors are black plastic or glass trays into which you add a solution that helps show the watermark (usually the letters USPS) added to the paper that the stamp is printed on. Again, sometimes a watermark is necessary to distinguish one stamp from another.

Other helpful stuff would include glassine envelopes for storing extra stamps, a magnifying glass for looking closely at a stamps condition, etc.