I've mentored brothers, friends, and my son. As others have said, there is much to do well before the shot. But, you already know that as you are asking this question to prepare yourself. Good on ya.
1. Pay attention to the animal's posture as the arrow hit.
2. See the arrow hit and note or project the exit wound.
3. Freeze in your mind where you last saw the deer.
4. Listen for sounds and look for flashes where the deer runs.
5. Mentally mark deer's location to find 1st sign and arrow.
5. Wait 30-60 minutes, get help if you can, stay off blood trail.
6. If in a tree, be safe, lower the bow, slowly descend.
7. Go to the where the deer stood, look for sign and arrow.
8. If you find the arrow stick it vertical where deer stood.
9. Mark that spot with a panel of toilet paper.
10. Staying to the side of the trail look for next blood.
11. Place paper waist to eye level as you find blood.
12. If you can't find blood in first 20-30 yards, stay off trail and go to the spot you last saw the deer. Look for blood there.
13. Continue looking, following, and marking blood.
14. If you lose trail, look back at paper and project likely direction of next blood.
15. Stop and look around from time to time, you may see the deer and shorten your trail.
16. It is VERY IMPORTANT to stay with the blood trail, it will lead to a dead deer. Patience is your friend and the scanvenger's enemy!
17. If you lose trail you'll have to fan and scan at least 180 degrees a few feet at a time looking for next blood -- pretend you are the wounded deer, check existing trails and barrier-free courses. Water sources are attractive to bleeding deer.
18. Oh, arrows and knives should be quivered and sheathed during all of this!
19. When you find the deer.
20. Watch and study for a few. Make sure it is dead. If alive or unsure (?) shoot again -- VERY RARELY needed.
21. Approach the animal from the rear or back in case it leaps up. Again, very rare.
22. Take Pictures!
23. You should have studied a field dressing DVD, lots of good ones. Field dress right away so the animal will begin to cool and your drag load is lightened.
24. Your field dressing hole should be as small as possible to remove entrails--genitals to sternum is plenty for now. Too large a hole allows dirt in. You can remove esophagus and rectum when out of the field.
25. Be careful. I shared the emergency room in Colorado with an elk hunter that stuck a Big Buck Knife in his thigh. (I had a kidney stone -- I'd have rather have had the knife!).
26. Be careful dragging. This can be very strenuous and fatigue and dizziness can sneak up on you. Get help.
27. If the deer you shot wasn't the biggest you saw, mark the location on an aerial photo and send it to me!
You have lots of time to study good books and videos. If your mentors know what they are doing, they can save you a lot of heartache and effort. Your state wildlife agency should have excellent references -- The Pennsylvania Game Commissioin is well known for quality videos!
If you hit your deer well (lung shot) with a sharp broad head and the animal was unalarmed before you shot, you should find it in less than 150 yards -- not always. I've found the vast majority of such hit deer in less than 70 yards over the years.