Those weekday Masses that are nor feast days will usually draw their opening prayers, prayer over the gifts and post-Communion prayers from those of the previous Sunday. For example, today is Monday, February 16th. I don’t think that we have a feast day today, so the prayers for today’s Mass will come from the 6th Sunday in Ordinary Time.
Now, here is a monkey wrench. During Ordinary Time weekdays, the celebrant is free to pick from the votive Mass options. For example, whenever my parochial vicar celebrates Mass at the local hospital chapel, he wlll choose a votive Mass for the sick. My pastor will sometimes choose to celebrate a votive Mass for vocations or for other necessities. That is when you have to do some jumping around in the Daily Roman Missal to see what is where.
At least for the Feast Days, you can pretty much go by the calendar day (as listed in the Daily Roman Missal) to get the propers and the readings.
Now, we are fast approaching Lent. Unless there is a feast day like the Solemnity of St. Joseph or the Annunciation (or, St. Patrick’s), the prayers and propers will be given for these particular Lenten days.
As for the 3 “presidential” prayers (opening, gifts, and post-communion), these can come from a number of sources.
If the saint of the day is a martyr, for example, the Mass for a martyr might be used (depending on the ranking of the celebration, which can get extremely complicated.) Apparently, you’re able to find them without any difficulty.
If you’re having a hard time finding them, that’s because on weekdays in ordinal time, it’s (usually) perfectly acceptable to use “any Mass.” Don’t take that too literally–it doesn’t mean “any Mass” but it means that the priest has many different options from which to choose.
The general practice is that on a weekday, the prayers from the previous Sunday are used. So if it’s the 6th week of Ordinal time, the Mass will probably be the 6th Sunday. This isn’t a rule, but a general practice, so your priest might do something different.
Ask your priest what his “usual practice” is for determining the weekday texts. If he follows the above pattern, it’ll be easy. If he “jumps around” and uses different Masses on the weekdays (which is perfectly sound practice) you might have a problem following.
The general intercessions may be composed locally. There are also suggested texts in the Sacramentary–which can be re-phrased. As long as these are in harmony with what the Church describes, that’s perfectly legitimate, therefore these prayers might come from almost anywhere. I would suggest not trying to follow along with the petitions, as this might simply prove impossible, unless the priest is actually using one of the suggested forms. Is it the same every day? If that’s the case, simply ask the priest what his source is. He would probably be willing to give you a copy if he uses the same text all the time.
I compared the presidential prayers with those of this past Sunday and they seem like they were what I remember from this morning’s mass. I tried to make a concious effort to remember a line or two from each of them but found I was too busy memorizing and not praying