Ok, so you are supposed to go to a conference, and don’t quite know what to expect. I fancy myself to be something of a conference veteran and here are few tips in no particular order:

1. Funds: look for a conference that has student awards. Some organizers will pay you for minor voluntary work. You can look for the McGill Travel awards. Try the usual methods to look for cheap tickets. Work out the costs before going. Typical heads to budget for: tickets, visas, conference fees, local transport, board and lodging, per diems.
2. Find hostels close to the venue, preferably places with a free breakfast. There is usually hardly any time to look for something to eat when you are adjusting to jetlag and there is an important plenary session early in the morning. If something is available at your place of stay, it can drastically help kickstart your day. Plus, it can be a good way to meet someone else who might be attending the conference too!
3. Money-saving tip: very few conferences will include lunches. But there will always be social sessions, and it is not always inappropriate to consider oneself invited! 😉
4. What to wear: At virtually all the conferences I have been to, the person in a business suit tended to look out of place. Oh, but I go to biodiversity conservation-related conferences, and every discipline may not follow the same protocol. If the conference has a business angle, bring a pair of dress shoes and a tie and business suit. Otherwise, wear what you might wear to an advisory committee meeting. It will probably get you through most of your day.
5. Would I know anyone there? If it is your first conference, you will not know anyone. But there are plenty of people like you. And they are all there just to get to know one another. Most of our disciplines are amazingly small. Eventually you run into the same people everywhere. And you will definitely meet some people whose work you have been citing since the first ever draft you wrote for grad school. Time to rub off the stardust! Volunteering is a good way to meet other graduate students.
6. If you are in a new country or exotic place, do spare at least two days to look around. You have worked hard to get to the place and you are probably not coming back again very soon! Look up tripadvisor and set off!
7. Try and schedule your presentation at an early session during the conference. People tend to notice you only at your presentations. And the chances of meeting the most interesting people (or people interested in your work) are highest after your presentation. Once you are done with your presentation, you can relax and enjoy the conference. Keep your business cards ready after the presentation.
8. Talk to anyone and everyone. Try and have a good time at it. Everyone is there to meet others. It is a new setting and none is completely at home.
9. Find time for a walk. It can be quite tiring to be closed in dark rooms with slide projectors all week. Try and go outdoors.
10. There will be a lot of paper handed out throughout. Sort only the useful stuff to take back home. Paper tends to get heavy while packing.
11. Contrary to the impression, conferences do take up a lot of productive time. It takes weeks of preparation (travel arrangements, making the presentation the works). And conferences rarely reject any abstracts. Conferences charge you a fee, and they will not turn away potential revenue (which is, you!). SO just because your abstract got accepted for a 2-minute speed presentation, doesn’t mean you should definitely go. You could present a poster at ANY conference. So choose your conference carefully.
12. Try and submit two separate abstracts at once. If one gets accepted as a major presentation, and you still present the other in some form, you maximize your output at the conference. Also, try and volunteer, moderate, and socialize. The more people you meet, the more you will take away.
13. Once at the conference, look at the abstracts beforehand and select the sessions you really want to attend. You will not be able to attend everything of interest. So do not be harsh on yourself when you miss out 25% of what you thought would be interesting. Sometimes you come across really interesting presentations in completely random sessions.