Guild poll/survey
Even if there was a thread of this before, we are not allowed to revive it. (necroposting)
If your guild is acitve during the same period of time, you could organize a guild-meeting and invite every participant into your squad. ANet added a function for squads to start a poll with all squadmembers. Players will have a big message on their screen which they can sign with yes or no. Everyon can see the results on the left, as there is an icon at every member which indicates his choice. (wiki: squad, readycheck)
Another function we use, the location markers. Especially during missions. Our leader sets up two or three markers on the field and we can walk to the marker we want. For example if we have 3 more guilmissions to go, trek, bounty and race. He tells us trek is star, bounty is heart and race is square. When we walk to what we prefer and the majority wins.
Sadly this type of vote is not secret, so everyone sees what everyone decides. Also you need a commander tag for this, which is not that cheap.
About the guild-message of the day
If you want your members to read it daily, you have to put information in there which is necessary for gameplay. We usually write in detailed information about the fastest dailies and waypoints/hints as well as the list for the karma agents (waypoints). As the guildmessage apperars on login and every game-link you put in can be read and clicked on, this works quite well.
Still, even with this little trick, polls are a pain to make. The number of people who really do not care at all is too high. Best would be to ask your members during a guild event, e.g. guildmissions. Those who are online and care, will say their opinion. Once they decided, discuss the result with your officers and make the final decision.