Open Question: moving in 3.5 months, when should i search for a job?

I'm currently working a 31-40 hour week job that i love. I haven't even told my boss yet, so that's the 2nd part of my question...when do I tell him? My tentative last day is July 23rd (in my head), so I want him to have plenty of time to hire and train a new person. my other problem is, right now all the jobs are looking for people for the summer. I am willing to do anything. I'll have a bachelors in child psychology, and experience in daycares, customer service, receptionist/office work, so I'm pretty much up for whatever. When should I start looking for jobs? I feel like it's too early to call other stores that I work at now and just "give them my name", but I'd feel so much better if I've made some progress, and companies at least have my resume and story. any help would be appreciated.