First thing is decide how many outputs your mixer is capable of, then how many you need to use simultaneously.
From your description have 2 stereo main outs, another 2 group outs, and several inserts so you should be able to fill up the 1010lt's 8 analog inputs if you so desire.
Start with the main outs. These are probably XLR or 1/4" jacks, so you'll need converter jacks to plug into the rca inputs. Run the 2 main outs into inputs 1 & 2 of the 1010. Do the same with the Group outs - plug into inputs 3 & 4 of the 1010.
Let's say you now want to record 4 mics onto 4 seperate tracks in magix. Plug the mics into channels 1 to 4 on the mixer. Pan channels 1 and 3 hard left & pan 2 & 4 hard right. Push the relevant buttons on the mixer so that channels 1 & 2 go to the Main out, and channels 3 & 4 route to the Group out.
In Magix, arm your 4 tracks to record. Select the inputs as Delta Left 1, on the first track, Delta Right 1 on track 2, Delta left 2 on track 3 and Delta right 2 on track 4. This will give you the Main outs on tracks 1 & 2, the the Group outs on tracks 3 and 4.
Run Outputs 1 and 2 from the 1010 into the 2TR In jacks on your mixer. These will probably all be rca. Now you can monitor the output from the 1010 through the mixer's headphone jack. Hook up your amp/speakers to the mixer's Control Room out, and you can monitor from there as well.
Now you're ready to record!