All I have to say to these people is:
The the frick on the stick and prepare your character BEFORE the raid! You are not wasting just your time. You are waisting 9+ people's time, money, mana, etc. We are not responsible for your character's needs. If you want to be on a raiding team, you need to put forth this effort.
Things to prepare yourself to avoid making me grouchy:
- Be early for a raid. If raid starts at 8pm and you login at 7:59pm you are late. You should be at the instance with all your required goodies ready to go at raid time.
- If you expect to be cutting it close, prepare everything beforehand. Repair, buy your potions/reagents/food and move your character to the instance you are running. Then all you have to log in and say "I'm here and ready to go!"
- Do not start some ambitious task before raid time. Agreeing to run an instance with others 30 minutes before raid time is probably not a grand idea. What can be done is something you can drop easily such as dailies (so you can afford your own consumables!)
- Offer to farm for materials for things you need. Don't know how to make Blackened Basilisk yourself? Go get the meat and find a friend to cook it up for you. Another good pre-raiding task.
- If you absolutely must mooch from team members make sure you thank them. Nothing's worse than having to hand over your potions to someone who is thankless and thinks they deserve your stuff.