Question: On Earth, the presence of tides due to the Sun and Moon influence certain currents and other movements of water. This in turn leads to different forms of erosion, which can transform a landscape.

I'm working on a moon that's tidally locked to a planet - pretty much identical to the Earth-Moon system, except that the moon is slightly more massive, and has an atmosphere, water, and life (thanks in part to a magnetic field).

How will the tidal locking - meaning a lack of tides - influence the geography of this moon? Will erosion rates be different? Will that land be shaped differently?

Answer: 
I don't think you'll get a magnetic field without faster rotation, and month-long sidereal day is not up to it.

Without tides from the primary you'll still have solar tides and tides from other moons (as with Pluto/Charon + 3 "regular" moons) and any libration if the orbit is not exactly circular and exactly over the equator. 

You get erosion from rain on the mountains weathering the rocks, and wind blowing sand. It doesn't need coastal erosion only. I think the overall quantity of weathering will vary more due to the kinds of rocks and weather patters, so you can tune for proper feedback even without tides.

The overall plate tectonics, mantle convention, and geologic processes don't have any influence from monthly tides.
I do not think tides have any considerable role in forming the landscape. An influence of storms and weather patterns in general is much stronger.

For example, consider Black Sea which had no visible tides for few last Mys. You cannot tell the difference from any other seashore in a similar climatic area.