If you need to stay overnight while attending your course, it is best to stay in the northern area of Lincoln, to minimise traffic delays in the mornings.
Here are a few that previous students have recommended:

Search on airbnb for places to stay in or near Sudbrooke LN2 2FD

Cosy self-catering one-bedroom cottage within walking distance:

Also, try these:

Rehouse Farm B&B B&B as well as a self-catering apartment for longer stays

Here are others that previous students have recommended:

Travelodge Lincoln city centre

Travelodge outside Lincoln

Ann Phillips B&B 4 Chapel Lane, Nettleham, LN2 2NX tel. 01522 823946 (very close, in next village) no website

Langdale Lakes B&B  Lovely, peaceful location a couple of miles from the course

The Rest in Lincoln

Newport Guest House  B&B  near cathedral (recommended by our students)

The Old Palace B&B  right next to Lincoln Cathedral

Good Lane B&B        

The Lincoln Hotel  

Premier Inn

The Allotment House  

The Old Vic B & B or Self Catering cottage