Above, the Mora 120 and below the Mora 106
The best starter spoon carving knife are Frost knives produced by Mora the Swedish company. They have triple layered laminated carbon blades and birch handles. My preferred knife is the the Morakniv #120, with a 59 mm blade length. The Morakniv #106 is also popular, with a blade length of 79 mm, but I personally find the additional length gets in the way.
The bext price bracket includes sloyd knives with hand forged blades from makers such as Svante Djarv, Hans Karlsson and Ben Orford based here in the UK. In the US, Del Stubbs makes quality carving knives
The choice of a carving knife can be a very personal one, and moving beyond the the utilitarian sloyd knives is a wide choice, some of which are highlighted on my knives page. The three keys to a knife that will be good for spoon carving are; no guard on the blade; a flat bevel on the blade (sometimes called a Scandinavian grind) rather than a knife with a secondary bevel; and a modest blade size.