What kind of skills do you need to start?

Layout technicians spend most, I am guessing 75%-90% on average, of their time in front of a computer screen "building" systems using AutoCad but in my opinion AutoCad skills are a small part of the skills required for the job.

High school graduate is a must.

Must have math skills equal to at least high school algebra I and geometry certainly doesn't hurt.

In my opinion reading and interpretation skills will have to be better than average. We're a heavily regulated industry and just the NFPA #13 Handbook has 1,200 pages full of definitions like Section 5.4.1 having to do with Hazard Classifications.

5.4.1* Extra Hazard (Group 1). Extra hazard (Group 1) occupancies shall be defined as occupancies or portions of other occupancies where the quantity and combustibility of contents are very high and dust, lint, or other materials are present, introducing the probability of rapidly developing fires with high rates of heat release but with little or no combustible or flammable liquids.
5.4.2* Extra Hazard (Group 2). Extra hazard (Group 2) occupancies shall be defined as occupancies or portions of other occupancies with moderate to substantial amounts of flammable or combustible liquids or occupancies where shielding of combustibles is extensive.
5.5* Special Occupancy Hazards.
5.6* Commodity Classification.
See Section C.2.
5.6.1 General.
5.6.1.1* Classification of Commodities.
5.6.1.1.1 Commodity classification and the corresponding protection requirements shall be determined based on the makeup of individual storage units (i.e., unit load, pallet load).
5.6.1.1.2 When specific test data of commodity classification by a nationally recognized testing agency are available, the data shall be permitted to be used in determining classification of commodities.
5.6.1.2 Mixed Commodities.
5.6.1.2.1 Protection requirements shall not be based on the overall commodity mix in a fire area.
5.6.1.2.2 Unless the requirements of 5.6.1.2.3 or 5.6.1.2.4 are met, mixed commodity storage shall be protected by the requirements for the highest classified commodity and storage arrangement.
5.6.1.2.3 The protection requirements for the lower commodity class shall be permitted to be utilized where all of the following are met:
(1) Up to 10 pallet loads of a higher hazard commodity, as described in 5.6.3 and 5.6.4, shall be permitted to be present in an area not exceeding 40,000 ft2 (3716 m2).
(2) The higher hazard commodity shall be randomly dispersed with no adjacent loads in any direction (including diagonally).
(3) Where the ceiling protection is based on Class I or Class II commodities, the allowable number of pallet loads for Class IV or Group A plastics shall be reduced to five.
5.6.1.2.4 Mixed Commodity Segregation. The protection requirements for the lower commodity class shall be permitted to be utilized in the area of lower commodity class, where the higher hazard material is confined to a designated area and the area is protected to the higher hazard in accordance with the requirements of this standard.
5.6.2 Pallet Types.
5.6.2.1 When loads are palletized, the use of wooden or metal pallets shall be assumed in the classification of commodities.
5.6.2.2 For Class I through Class IV, when unreinforced polypropylene or high-density polyethylene plastic pallets are used, the classification of the commodity unit shall be increased one class (e.g., Class III will become Class IV and Class IV will become cartoned unexpanded Group A plastics).

Protection requirements are found throughout the standards and below I've included a snapshot dealing with the protection of idle wood pallets using control mode sprinklers.

This represents just one page out of the 1,200 or more contained in the handbook.

It isn't the worlds easiest reading and you're not going to breeze through it in an evening.

It also needs to be recognized in addition to the NFPA #13 Handbook we commonly deal with NFPA #14 having to do with standpipes, NFPA #15 having to do with water spray systems, NFPA #20 having to do with fire pumps, NFPA #24 having to do with underground fire line and hydrant requirements and then there is NFPA #25 having to do with inspections and testing.

On top of the NFPA standards there are building codes that you would need to be familiar with, at least those sections having to do with fire protection, and then there are a number of insurance company standards.

In addition to the standards there's manufacture's literature that a technician is going to have to read and fully understand.

There are literally thousands of different kinds of sprinkler heads and nozzles available on the market.

For an idea of the number and complexity visit Viking Corporation.

I would have to say reading skills and comprehension rank right up there.