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For M104 I do similar to the following:
1. Rough align by placing tripod feet into usual circles (black texta-color marks) on driveway concrete;
2. Balance scope - optimise for direction of M104;
3. Use Mintron video camera fed to a TV for polar alignment (I only ever need a small horizontal adjustment); Ensure no/little DEC drift over 3 mins.
4. Load the Canon 350D camera and connect video cable to TV.
5. Get focus exact using a Hartmann mask and a bright nebula;
6. Do a rough two-star Goto Alignment (LXD-75 mount) via Telrad/finder;
7. Test Goto accuracy on some bright targets;
8. Goto M104;
9. Take 15-20 second exposure;
10. If M104 is visible in the photo when reviewed on the TV then centre it by comparing the location of brightest stars on the TV with the ones visible through the cameras optical viewfinder (this is easy);
11. If M104 is not visible assume it is easily within 2 degrees of where you're currently pointing (Goto won't be that far off) so use your Telrad to take 20 second exposures one degree up, down, right and left of centre. The field of view of the Canon 350D camera in an LXD-75 SN-8 (focal length 812mm) is about 1.6 degrees so it doesn't take long to find what you're looking for. M104 is very bright and you will definitely see it like a large bright streak on the image when you nail it;
12. Centre M104 as per step 10;
13. Take 50 exposures (ASA1600, 30 secs). Align and stack the best of them (the ones with no star trails) in software (eg. MaxDSLR or similar).
14. Do a Log stretch;
15. Histogram the black points on Red, Green and Blue;
16. Histogram the white and mid-point to taste;
17. Create a Luminance layer from Red, Green, Green converted to Mono;
18. Histogram to taste;
19. Apply noise reduction/blur technique - unsharp mask, blur or some such (also consider Noiseware);
20. Sharpen slightly (very slighty);
Hope this helps.
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