I think your design is a great step towards a two-kerbal lander. Some points:
1. Lower the landing gear to their lowest possible extent. If you come in hard, you will want the gear to have as much travel as possible to absorb impact. You run the risk of damaging (destroying) your engines if you come in hard. You are handicaping your gear's ability to save your craft from bottoming out.
2. You need RCS thruster blocks and fuel. They will help in attitude control when you go in to land.
3. I notice you don't have docking ports, so you likely don't have any stations. These are good to have early on, as they give you more options down the road. Things like rescue missions and refueling operations require them.
4. You can never have too many parachutes. Put four drogue chutes on, and stage them first. If you replace your center chute with a docking port, put four radial mount chutes to stage last, otherwise put two more radials on. It sucks to come in to fast after a long mission and blow everything up on impact.
5. Action group your solar panels. I assign them to one with my radiators. Two deploys drills, three starts/stops the drills, and four runs all my science, to include crew reports. This will save you time and aggravation down the road as well.
6. Your science jr is fine; I had mine in a similar location. You can EVA your scientist into there, and do resets and such. Just make sure you always retract your panels when on an EVA!
7. consider adding a few lights. I have some pointed up, to help with docking, and a few pointed down, do help with depth perception when landing. I put some low power service lights to illuminate hatches and ladders, and your science jr could use some illumination inside the bay.
Things to consider:
A. Set up a station network. They don't have to be special, just hold fuel and have a docking port. Radial ports are ok, but lineal ports allow for expandability. KSP will be upset that you have a docking port for a decoupler, but strutted up properly, they are way more useful, and have no rigidity issues. Just make sure you put docking ports on the right way!
B. Mechjeb. I swear by it. Landings become point and click. Docking becomes manageable. There are tons of mechjeb tutorials. My craft look naked without the MJ module attached.
Zeb