Some of these steps may take less time than I'm giving you, but this would get you done by 30.
Age 18: Study, take GED review class, take GED
18-19: Enroll in community college, meet with advisor, discuss what is needed for pre-nursing at local CC and university offering BSN. As other poster suggested, consider taking a CNA course or preparing in some other way to get a hospital job and begin to be exposed to the profession.
19-20: Take pre-nursing courses, seeking help from tutors, study groups, anything available on campus that you need to ensure good grades, since you are probably out of practice for studying. Consider whether or not you can afford to get a BSN immediately, or if you'll need to get your ADN first. Either way, take BSN prerequisites as well - you'll need them eventually.
21: Apply to nursing programs
, wherever you've decided you'd like to go. Try to keep your grades competitive (more As than Bs, avoid Cs and lower). If you are placed on a wait list (which many community colleges do), continue taking BSN prereqs and consider applying to the university program - you may graduate with a BSN before you're off the wait list at a CC. If you work at a hospital, they may pay all or most of your tuition.
21-23: Earn your degree, whether at a CC or university. Both programs take about 2 years for the nursing component at most places. Graduate, study for the NCLEX, get your license, and get a job. Apply for ICU jobs, you may or may not be able to find one without a year of MS first. Depends on the economy, how you interview, what hospital experience you have, and where you live.
23-25: Get ICU experience, 2 years is required by many CRNA schools anyway so good choice. You'll want to work in a fast-paced ICU with very sick patients, dealing with vents and multiple drips on a daily basis. If you don't start in one, transfer. You'll need BLS and ACLS just to work, and PALS before you apply. If you haven't already gotten a BSN, you'll need to take classes part time while you work. This may add a year to your ICU experience. You'll also need to take the GRE, and probably the CCRN. Look at requirements for CRNA programs you're interested in. You may need to take another chemistry course, or wish to try a graduate course in patho, statistics, or something else.
26: Apply to CRNA schools. Get good recommendations, and hopefully get a few interviews.
27: Start CRNA school
29/30: Graduate and take your boards!