The 33-year-old was a free agent after leaving Leyton Orient at the end of last season.
Scunthorpe have now signed 10 new players this summer.
Henderson scored eight goals in 25 appearances for Orient last term following a move from Nottingham Forest.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Curzon AshtonCurzon Ashton | 20 | 13 | 3 | 4 | 29 | 11 | 18 | 42 |
| 2 | Scunthorpe UnitedScunthorpe | 21 | 10 | 7 | 4 | 35 | 15 | 20 | 37 |
| 3 | Kidderminster HarriersKidderminster | 20 | 11 | 4 | 5 | 31 | 16 | 15 | 37 |
| 4 | King's Lynn TownKing's Lynn | 21 | 11 | 4 | 6 | 26 | 19 | 7 | 37 |
| 5 | Buxton | 21 | 11 | 2 | 8 | 34 | 24 | 10 | 35 |
| 6 | Chorley | 21 | 10 | 5 | 6 | 30 | 25 | 5 | 35 |
| 7 | Alfreton TownAlfreton | 20 | 9 | 7 | 4 | 25 | 19 | 6 | 34 |
| 8 | Hereford UnitedHereford | 20 | 9 | 6 | 5 | 30 | 19 | 11 | 33 |
| 9 | Brackley Town | 19 | 10 | 3 | 6 | 23 | 16 | 7 | 33 |
| 10 | Chester FCChester | 20 | 9 | 5 | 6 | 25 | 21 | 4 | 32 |
| 11 | South Shields | 22 | 10 | 2 | 10 | 37 | 35 | 2 | 32 |
| 12 | Spennymoor TownSpennymoor | 21 | 7 | 9 | 5 | 31 | 24 | 7 | 30 |
| 13 | Darlington | 21 | 7 | 9 | 5 | 25 | 21 | 4 | 30 |
| 14 | Scarborough AthleticScarborough Ath | 20 | 7 | 7 | 6 | 24 | 23 | 1 | 28 |
| 15 | Peterborough SportsP'boro Sports | 21 | 7 | 6 | 8 | 25 | 28 | -3 | 27 |
| 16 | SouthportSouthport | 21 | 7 | 6 | 8 | 25 | 31 | -6 | 27 |
| 17 | Leamington FCLeamington | 20 | 6 | 5 | 9 | 23 | 22 | 1 | 23 |
| 18 | Oxford CityOxford City | 21 | 5 | 7 | 9 | 31 | 38 | -7 | 22 |
| 19 | Warrington Town | 22 | 4 | 9 | 9 | 20 | 29 | -9 | 21 |
| 20 | Farsley CelticFarsley Celtic | 21 | 6 | 2 | 13 | 21 | 38 | -17 | 20 |
| 21 | Marine AFC | 21 | 4 | 6 | 11 | 12 | 26 | -14 | 18 |
| 22 | RadcliffeRadcliffe | 20 | 4 | 6 | 10 | 23 | 39 | -16 | 18 |
| 23 | Needham Market | 21 | 4 | 5 | 12 | 14 | 34 | -20 | 17 |
| 24 | Rushall Olympic | 21 | 3 | 3 | 15 | 18 | 44 | -26 | 12 |
| > National League North Full Table | |||||||||
